Now, those campaigns no longer exist. I’m not fully sure why they were stopped. Maybe because of spam or misuse, but I honestly believe not every newcomer is a spammer.
Altcoin bounties used to have jr member spots, but these altcoin bounties themselves are rare sight these days, much less a worthy ones and forum has no involvement in this, altcoin projects themselves stopped having interest in forum as place for their promotion.
By the way, I just checked bounties section for you and there is one for jr members:
https://bitcointalk.org/index.php?topic=5554005.0Now, whatever existing, altcoin bounties are absolute shit since last few years, above mentioned looks no exception, but it may help you with motivations.