It's understandable they might require a phone number to keep down spam. It's less understandable they'd lie to new users on the reasons their account was blocked. We can't expect even the smallest scraps of honesty from corporations anymore.
I am not sure people realize what a high percentage of users of "free" services are spam bots of some sort. Sit around in the average Twitch channel and you'll see a flood of spam from similarly-named accounts every so often. They get around the filters because Twitch tells you why you're filtered. "This room is in followers only mode", so they follow the stream they want to spam a few days/weeks in advance. "This word is not allowed by the spam filters", so they change one letter and continue spamming that word. Etc., etc.
It sucks for normal users caught up in spam filters, but it's an enormous problem that there is no easy solution to.