Twitter has been banning and shadow banning people for years without clear communication, although with clear ideological bias. This has been a growing problem, but Trump was unwilling to stand up to them, until he was the target. It was predictable.
You can oppose the ban and the man, although the ban is a much bigger threat. He was voted out, for goodness sake, now they’re trying to turn him into a martyr. Bad move on Twitter’s part.