Yi is still going to be built tanky even after the PBE changes
As much as his "tanky" build is cancerous (
for example) this is unfortunately still the only viable way to build him, at least on higher elos. Being a melee and not having a way to instaburst someone like Talon or Fizz, nor having a way to control the teamfight like Yasuo, the only way that Yi can do his job without being CC-ed and instabursted himself is by building him tanky.
This is a problem that just changing his E is not going to solve. Unfortunately I don't have any ideas to make him work full glass cannon like he should.