I agree. It'd be too much to expect it to happen now, unless Asami has a moment of weakness where she lets him inch his way back in. I'd say it has a chance of happening buuuuut it has plenty of reasons not to. Mako kinda dropped the bombs =/
Mako barely has his brother, yes, the worst X.X. If Korra is still up in the air on her feelings regarding Mako, it wouldn't have been wise to keep him around, especially when she's trying to rekindle her friendship with Bolin to be as strong as it used to be before the dumb kiss X.X
I agree that any tenderness between the two would've been ...stepped on by Meelo's silliness, as well as Ikki's mouth, and I think Jinora would probably ask them extensively about their past romance ( for hilarious results ). Tenzin's got four kids now so thankfully any sexual tension should be quite under control xD but you don't forget your first, I hear. So you WOULD be down for some civil unrest directed at Tenzin and, in turn, Lin?
Can't wait >_<