The upcoming Vanguard update and Sion

Reasons why I enjoy Sion are simple: It's fun to play this hulking, near-unkillable behemoth who charges into the battlefield (I. AM. WAAAAAAR!!!!), yet unlike Malphite, has interesting abilities with nebulous success/fail cases. Also unlike Maphite, he's not a total pushover in lane, and can actually do some serious damage, provided you land your E and Q.

I am worried that since Malphite effectively occupies the same role as Sion, but is more forgiving and less rewarding, they will try to make Malphite more like how Sion is now. I can totally see Riot then wanting to seperate Sion and Malphite by trying to double down on Sion's undead theme. For example, making him more about engaging, dying, and then still being a huge threat with his passive.

TL;DR Update to Malphite likely means his abilities are more interesting/difficult, which would force Riot to update Sion in a different (possibly unwanted) direction.

Thoughts?