So how will theses sources books that have been release work this one DND. From my understanding one, is supposed to be backwards compatible with 5e. How will subclass of 5e class work with one class, or will one be releasing updated version for all the subclass

Also what about the artificer, while they be an update version of this class sent out along perhaps added into the new players handbook, or is there going to be another source book released with and updated artificer 

At this time, no one knows the answer to that - likely not even Wizards, since the exact handling of the Beyond release is going to be partially determined by how they plan to update D&D long-term, and that has not been fully decided.

Likely we will see the old Core Books be listed as Legacy content and no longer available for purchase, much like was seen with MMM’s release. Unclear what might happen to Tasha’s or other supplemental core books—that will depend on how they interact with the new core books. 

I expect Adventures will remain available for purchase, since they are supposed to be compatible and there is no reason to stop selling something which would still be profitable.

I know that is not the most helpful of answers, since it is fairly speculative, but the simple reality is there are no real answers right now, and we should not expect any answers until sometime next year.

I don’t believe they’ve mentioned the artificer at all, in any context. Pretty sure they’re not touching it. Almost certain it’s not going into the new PHB. 

People have been asking these or similar questions on virtually a daily basis for months.  There simply isn't any information right now and won't be until WOTC decides to make an official announcement, which at the very earliest would probably be at GenCon.  Just keep checking the front page on DDB- if there's nothing there then nobody on the forums is going to know anything.

Browsing the forum and using the search bar is your friend.  The answer just isn't public.  However logic given the class count One D&D has presented seems the Artificer will be left out of the initial core.  Maybe it'll show up in a future product.  

Like the above responses we don’t know exactly. 

A few things I feel is pretty certain

There are 12 classes with 4 subclasses each in the PHB. They pretty much stated that outright. Sorry no artificer. Unless they surprise us with it prior to release. 

Playtest 6 says for subclasses, that will be in the PHB, that were in Tasha’s to refer to that sourcebook. And in playtest 6 they reverted subclass progression to the 2014 progression, except all start at level 3. So if there is a subclass in any previous sourcebook you want to play with the 2024 PHB base class, you can fairly easily. Wether or not you will have access to that book remains to be seen but most likely if you already purchased it on DDB you can still. Not sure if the character builder will support pre-2024 subclasses either. 

Quote from Xalthu >>

I don’t believe they’ve mentioned the artificer at all, in any context. Pretty sure they’re not touching it. Almost certain it’s not going into the new PHB. 

 They have, they just haven't said much. It's been a while and I'm not sure where exactly it was, so I'm not going to say much beyond it's not going to be in the PHB (which I'm really disappointed in - it means that the 1D&D Artificer will most likely suffer the same problems as the 5e one), and that they'll look at it for a later release. Which is to say the one thing we know for sure (as.far as that goes when the book's not been released) is that it won't be in the 1D&D PHB.

Quote from ThriKreenWarrior >>

Like the above responses we don’t know exactly. 

A few things I feel is pretty certain

There are 12 classes with 4 subclasses each in the PHB. They pretty much stated that outright. Sorry no artificer. Unless they surprise us with it prior to release. 

Playtest 6 says for subclasses, that will be in the PHB, that were in Tasha’s to refer to that sourcebook. And in playtest 6 they reverted subclass progression to the 2014 progression, except all start at level 3. So if there is a subclass in any previous sourcebook you want to play with the 2024 PHB base class, you can fairly easily. Wether or not you will have access to that book remains to be seen but most likely if you already purchased it on DDB you can still. Not sure if the character builder will support pre-2024 subclasses either. 

I would like to emphasize some of the facts that Thrikeen Warrior mentioned. The subclasses in 5e and 1DD will almost certainly not be the same. However, assuming designers keep the standardized subclass level progression (which is what will probably happen but we can't be sure), then it will be significantly easier to mix and match subclasses from across editions. The power level might be a difficulty in some scenarios but you'll most likely be able to use subclasses from 5e and 1DD together.

Ultimately, though, we don't know how compatible the books will be with each other and in what ways they will overlap. You'll probably have to wait for all the answers to your questions until 1DD comes out.