Whetstone and Chalk

I just found out today that whetstones and chalk were removed in 5.5 rules.  Can anyone explain?

Likely because neither had game-specific rules and therefore don't need to be listed in the rules. That doesn't mean they don't exist, just they're not something that requires detailing in a mechanical, rules sense

A whetstone was pretty much completely pointless in 5e, given that even the optional rules didn't include anything for weapon maintenance. Chalk I could take or leave as adventuring gear, although pinning down the life of the basic listed piece would probably be a nuisance. Maybe express it in square footage? I dunno; if they made it work with ink I think they could have with chalk, but it's not a glaring omission either.

Chalk (used for things such as marking passages in dungeons) is commonly enough used in games that it seems worth an entry, though probably not much of one.

If it isn't in the 5.5 books, it doesn't have a 5.5 version.

It'd be an impractical move to either remove the Legacy tag or make a duplicate entry.

There's more, albeit still minimal, value in putting back the 2014 Lance.