It seems that Second Thought (and their second channel, First Thought) has been silently removed from Nebula, with no comment from them or anyone on Nebula's side.
There's some context in the comments of a couple of reddit threads about this, that have been deleted on the Nebula subreddit:
Random user: @JT How come First thought releases this week aren't showing up on Nebula?
JT: FT, ST, and The Deprogram are no longer partnered with Nebula. It wasn't a good fit anymore.
JT: We mutually decided it was time to part ways. Some Nebula creators wanted me to make a clarifying statement on my position regarding Israel and Palestine and it was getting too close to a "both sides" thing for me, which felt like compromising my principles. Just a difference of priorities. Business optics versus taking a principled stance.
I thought nebula was run by the creators essentially. At least that's how it's presented in the ads for it, so it does sound like this is nebula forcing creators to hide their opinions.
The guy said that Hamas is fine because he doesn't think there are any Israeli civilians. Something even Hamas disagrees with. When he refers to "both sides" here, he means that he doesn't agree both sides have human beings getting hurt.