Arguable, since we don’t know if those will be updated, or if the full new crit rules will make it fit.
You still make a check to escape a grapple, and to initiate it. At most they may need to errata some features to take out the “strength (athletics) check” before “to initiate a grapple”.
So a hypothetical incompatibility, maybe?
Please list the rest. I’m pretty sure these minor erratas (at worst) are far more than half of the full list of supposed incompatibilities between the playtest and the existing rules.
I am saying if you right now attempt to play the playtest rules along with your existing PCs, they will immediately need a house rule to make some of them work.
Here's some more.
You have a Variant Human or Custom Lineage feat that is a half-feat with a bonus to an ability score so you could start with an 18 in that stat at first level. Not compatible with these playtest rules.
Adamantine Armor - Does nothing now.
Spore Druid Fungal Body class feature (14th lev) - Most important part of it now does nothing, and there is no easy house rule to address that. And as it's from a supplement, and we have no indication they will be updating every subclass in every supplement, it may just end up staying that way.
Grave Cleric Sentinel at Death’s Door class feature (6th level) - does nothing now, there is no easy house rule to address that, and as it's a supplement may never seen an update.
The grapple issue impacts raging barbarians, rune knights using giants might, heck even the plasmoid from Spelljammer release literally the same week as these playtest rules has an ability that is no longer compatible with these rules.
We have a TON of issues with short rests being phased to be only for hit dice recovery and not for restoring certain powers on a short rest. All those things in books outside the core 3, we have no reason to believe they're all going to get updated. So they're directly in contradiction to the new core philosophy of not encouraging short rests for regeneration of powers.
Clockwork sorcerer chooses from certain spell lists which may no longer exist once they shift to arcane, divine and primal spell lists.
And this is just the first playtest package of 11-17 more monthly packages. My greatest concern is for all those supplements that are not the core 3. We know they will replace the core 3, but will they offer an update or errata for all the other books or just leave them behind like they did for 3e when 3.5e came out? I think it's reasonable to assume the later.