[Blau]

You still need to do after finishing it while lvl 100is reached.
And no, stats still don't get affected.
That's also why i said, if Stats aren't like on calc, put to storage. 

It's about growth rates etc. Which i Don't have indepth knowledge of.
But on lvl 100, stats will be maxed.
No matter if evolved at lvl 16 or 100.

ok then, thank you, i will try it once i get one of them at level 100

my Landorus-therian reached level 100 and i put into the storage like you told me to but nothing changed in its stats

Like i mentioned, it only does if stat changes happen, after the option to lvl up is Gone.
Like doing ev train / adjustment after reaching lvl 100.