I've been meditating about this issue and finally decided to revert the change of status that was done to Thomas based on information from the latest Q&A due to being unreliable.
The problem with these Q&A sessions is that what we know about them doesn't come from official sources; i.e., they're not compiled in a magazine or guidebook but they come from Twitter accounts of people who claim to have attended the event. It's easy to see that the chances of some of them being fake or inaccurate are high. There are even some contradictions in the reports of the latest event; for example, a user reports Isayama saying that Eren's blood type is B, while another says that Isayama suggested that it might not be one of the 4 real-life blood types.
Even if we were to assume that all reports are authentic, some accounts depict Isayama's editor getting nervous that Isayama might just be letting himself get carried away with his answers, and Isayama includes a sort of disclaimer:
“Ultimately, the story resembles a living creature in the way it evolves. My answers during this autograph event are just some of all the possibilities that can happen. I hope you can ask questions while having this idea in mind.”
The information about Thomas specifically is even more problematic as it comes from a Tumblr account that ironically links his wiki article as source (this might be a mistake from the author).
In conclusion, I think we should avoid adding any information from these sessions to the wiki as they don't meet our quality standards until they are backed up by more reliable sources.
The people reporting this might be lying, true, but I take issue with Isayama's editor's reaction to his answers being any sort of indication that we should discount information that Isayama (is confirmed) to give out. Isayama is the driver of this car, no matter how much backseat driving his editor tries to do.
I'm fine with reverting the information. I would be more comfortable including stuff from the Q&A if it had come through an official source (or a recording of the Q&A) rather than personal reports where the person tweeting could have misinterpreted something.