Mages aren't supposed to be able to stay out for too long anymore, are they?

With the 6.9 changes tonight, we now have a problem for our mana mages: If you're in a siege or long-term "can't recall or we lose" scenario, how do you continue to stay out in the field for that ultra-long duration?

ADCs and Fighters (and occasionally Assassins) have lifesteal Tanks and juggernauts have life regeneration Supports have mana regeneration

Mages get... nothing for sustain.

Probably intended, right?

If so, that proves that Riot hates ultra-long term combat scenarios (i.e. Baron/Dragon jockeying, sieges, etc).