What happened to the esports tab

Same, I can only access from history

Who knows and honestly, who cares at this point for reason that Riot has stated that they won't post any team updates or news anyways within the LCS.

https://boards.na.leagueoflegends.com/en/c/community-moderation/8ZKpVEaJ-why-esport-section-of-boards-dont-show-up-anymore-in-the-list-of-boards-sections-on-the-left-menu

Goodbye esports tab. The world couldn't know how unpopular you were lest they know the truth about Riot esports.

a simple solution would be to favorite a forum with esports (like this one) and then use that tab to click esports, annoying but it works for me.