or possibly larger base health pools and base health regeneration, giving some tank items base health scalings for example to prevent abuse cases.
since juggernauts have high base health too this shouldn't be an issue for them either if they want a few pure tank items in their build.
you could make a case for Sion getting higher base resistances since he has to farm his health pool, and this health pool could also be considered base health if they go with base health scalings on items
This would mean that tanks will prefer to build additional resistance items and items which synergize with base health.
and juggernauts will most likely opt for the hp + damage hybrid options like cleaver, steraks and titanic hydra.
Sion will definitely end up in a weird spot during this update since he is more of a tank/juggernaut hybrid with a weird way of acquiring stacks compared to all the rest of them as in he has to farm his stats
But there are options for riot to handle that as in giving him more base stats in regen & armor or making his farmed health into base health as opposed to bonus health if that would make sense in the light of item reworks