This is definitely not new, and is among reasons I left. I lost count of the number of times a manager (who was later promoted to a leader) claimed others' work/projects (mine included and he wasn't even my manager) as his own on large group calls. This was in Corporate Communications for reference and he's still there...
He wasn't the only one. I even had direct colleagues that were just plain nasty/bullying on calls, via email, etc. One finally got moved because the internal leader client couldn't stand working with this person (though they STILL got a promotion prior to getting moved off the client beat).
My only guess with the peer (and manager) bad behavior is their own insecurities.