Oh. They made the DC lower for Constrict its now only grappled. But at least they have multiattack now.

Fusion time! Use this Anaconda, but give it the DC and the Restrained condition of the old one. If you want to make an Anaconda, give this guy the Crocodile's Hold Breath trait. 

The constrict part is still confusing to me. Let's take a case where the snake successfully constricts a target. In the old rules, it would do this with an attack; in the new rules, the target fails a save. Either way, the target now has the grappled condition. The thing I'm confused about (with both versions, actually) is this: the next time the snake uses constrict, does the current grapple end on the target on a successful save (or a failed attack roll, in the old rules), or does the target merely avoid taking additional damage?

The rules on ending a grapple state:

A Grappled creature can use its action to make a Strength (Athletics) or Dexterity (Acrobatics) check against the grapple’s escape DC, ending the condition on itself on a success. The condition also ends if the grappler has the Incapacitated condition or if the distance between the Grappled target and the grappler exceeds the grapple’s range.

Since none of this happens on the second use of constrict--ie the target isn't using an action to end the grapple, the snake isn't incapacitated, and the distance between the target and grappler haven't changed--RAW would seem to indicate that the original grapple persists. The way this new version of the snake is written, a target uses their save to prevent a new grapple, not to end an existing one... I think?