If there hasn't been a non compete clause or agreement, yes. But those are common, as otherwise Netflix has paid for content that the creators can then sell on to rivals. It would be interesting to know, but also we may not find out, commercial interests, secrecy and all that.
What's your source btw for all Netflix's animation being cut? That's not what the reports I've read say - which is that the head of original development has gone, plus several key staff, but not all animation full stop. Several high profile projects, one of them being Pearl, have been dropped but again not all.