Yes this is a legitimate thread because it was created by Cartesi's own account. I don't know why ANN has 2 but I don't think this will be a problem.
Cartesi has a good developer so it's worth following.
There was an error with creating that other thread. It has now been locked. Apologies and thank you for keeping a close watch for other potential fraudulent accounts!
We could have moved to the new thread started by you @Cartesi.
But is your call. Good luck!