Khabib only matches up well against Mcgregor, and even then his awful striking could lead to him getting finished. Even if McGregor was a bad matchup stylistically for Khabib, it makes sense to wait for him due to the payday.
Fighting either Aldo or Tony before McGregor is a TERRIBLE business decision, especially if it's only for an interim belt. We've seen that interim belts do not necessarily mean the champ will fight you, and they certainly aren't worth jack shit legacy wise.
Aldo beats Khabib decisively, and Tony simply mauls him over 5 rounds. Khabib lacks the striking and ground game to threaten either guy even if he gets them down. He has a better shot vs. Tony due to his incredibly stupid and useless rolling leg lock attempts and tendency to d'arce. But Aldo he absolutely cannot win against. Aldo has better TDD than Tibau in that he simply sprawls and pivots. Khabib can't hold him or repeatedly try takedown attempts against the fence for Aldo is too quick.
Khabib should wait for McGregor. Even if it means letting Aldo vs. Tony get an interim title, all he has to do is keep talking shit and the UFC will make the fight over a unification bout.