No, here's how it worked.
Veigar's cage was too reliable and didn't have any counterplay to it, and shut down the mobility meta of the LCS, so Riot reworked, I'm sorry, gave him "compensation" for the removal of DFG by completely gutting his kit. He was supposed to get the dash cancel on his kit right away, but for some reason instead of just iceboxing the "rework" until they fixed it, they shipped it out anyways, and a broken cage, alongside an obnoxiously long cast time plummeted his winrate down to 38%.
After a couple of buffs, he stopped being complete trash, but people realized that he still needed more reliability is his kit. So they cut down the cast time to his W and gave AP on assists, which were huge QOL buffs, but then they realized, "oh shit, Veigar actually has a fuckton of damage." And the fact that he was made insanely more reliable due to the buffs to his W and E, he could now dish his natural ridiculous amounts of damage with impunity, hence why he's so strong now.
Really, all he needs is to get rid of the %AP damage scaling on his ultimate, and maybe tweak the base values of his damage dealing spells and the duration of his stun and he'll be balanced.