At this point, they might as well make him into a support champion because jungle clears are going to take all day long.
Remember this change to him in season 5? Riot wrote this as they nerfed his w to focus his power into his e:
"By being the cornerstone to both his offensive AND defensive ability, Titan's Wrath forces Nautilus into a playstyle that is very binary - break the shield and he's harmless, or suffer if you fail to do so. Shifting power into Riptide lets him clear faster and take more actions per teamfight, which are two key areas we thought were weighing him down."
What's the point of even having riptide anymore? It was a nice aoe ability for jungle camps but clearly he is being pushed out of that position and into lane so it might as well get reworked into something else. They focused all his power in season 5 into riptide and now it is going to be lousy.
As an added bonus they are going to nerf the health on all the tanky items which is awful for him because his shield scales off health. So now he is getting indirect nerfs to another ability as well because of items which is ridiculous for a champion that has narrowly below a 50% win rate right now.
This tank update at midseason better err on the side of tanks being too strong because right now Nautilus is the only tank with top 10 play rate in top lane (and he'll probably be out of it after these nerfs) and Amumu is the only jungler that is in the top 10 for play rate (and I assume he'll get nerfed soon as well). We're not getting a lot of incentive from Riot to play tanks and haven't been for a long time.