I'm sure I remember this coming up in the early days of the grounding, and it being described there were nothing like 34 Max simulators - which went along with it being portrayed as the same as an NG, plus a Powerpoint presentation. Air Canada had one, as the 737 was new to them, and Ethiopian had one as well, but there weren't many others.
I also recall the established 737 crew who had done the Powerpoint and were suddenly presented in a rearrangement with their first Max flight, and said afterwards it was notably different to what they had been given to believe.
I presume the sims will need new software to replicate accurately whatever MCAS or its replacement does, this being a key part of the training. As we know it hasn't even been certified yet what those changes are, once agreed the sim manufacturers are going to have to then develop, test and deploy the new sim software, and train instructors, before training can even start.