It's the fact they're in this skin line when they're both already in the Star Guardian line. We were promised a shonen-inspired line and got two of the same fucking champions as are in SG.
That's where the bullshit is.
Edit: To clarify, I'm saying it's really stupid that they hyped us up for a new, unique skin line featuring different champions only for 2/5 to be champions who are in the other line, and the sixth to just be the on-release skin for the cat. It'd be just as annoying if they had gone with MF, Jinx, Syndra, Poppy, Lulu, Soraka, Janna, or Ahri.
It's lazy of them to pick the two easiest champions to make skins for. The ones whose personalities already match the skin line, so even despite all new lines for the skin Ezreal just sounds like he's saying the same things he says by default. And instead of doing the work to design cool new effects for a champion that might be difficult to do on, it's the ones with the biggest, flashiest visual effects which are easiest to make new effects for.
There are plenty of champions they could've picked who would've actually been different. And it's kind of annoying the skins are obviously going to sell well because they copied the 2D style effects from FighterZ and Smash Ultimate.