The only bad or negative thing for me here is the centralization.
With a company like Meta, the centralization will be the problem and the privacy. As you recall before, there was an issue about data privacy with Facebook (Now Meta).
So if ever they will start become popular and lot of people will use their products especially NFT/Metaverse related, I am afraid of that issue for them.
Centralization is not a problem for most of these people. I mean I get that it is not something that would be great for many people who see it as centralized, but at the same time majority haven't cared about that for a long time now, so why should they care about it today?
Facebook will not really secure it too much, but if you trust Avax and its creator, SOL and its creator, Matic and its creator, I am sorry but there will be plenty who will trust Facebook (meta) as well. Not because it is a good thing, but many years ago people ended up giving up the power of decentralization and just let the teams take control over projects and they were fine about it.