Fuck no.
RDA is good, but he's nowhere near the all time books. I've not even heard him mentioned in top 10 LW's all time list.
Mendes is very good, though I haven't seen him in a top 10 FW list either.
He has an incredibly good win over Aldo.
One incredibly good win isn't enough to get the biggest achievement in UFC history.
If Cloner can beat Aldo again, Edgar, RDA, Cowboy, and about 5 others, then he's there.
Just look: Bones beat Shogun, Lyoto, Hashad, Bader, DC, Rampage, Vitor, Shael, Glover, and Gus. GSP beat Fitch, Alves, Kos, Hughes 2X's, Penn 2 X's, Hendricks, Sherk, Hardy, Serra, Shields, Condit, Trigg, and Diaz.
For Connie to beat Aldo again, Mendes again, Edgar, RDA, Cowboy and 5 others isn't a stretch when you're talking biggest achievement in UFC history.
Even if he does all that, that would just leave him a little behind GSP and Bones.
He would have to do more and do that while not losing a fight.
So at 2 or 3 fights a year, he has to fight for 5 more years to catch up to where they are right now. And that's assuming GSP never comes back, Anderson doesn't go on a hot streak and Jon loses.
I expect Cloner to lose either his next fight or fight after that.