I have several speculative concerns about this update that I'd like to voice, I'm sorry if these have already been brought up in this thread as I haven't read through the whole thing.
tl;dr:
1. I feel that limiting 1 oil per base and removing grey unsockets will result in additional unsatisfying grinding for base items and perhaps even more time consuming repetitive cube tasks rather than less.
2. I feel that consolidating runes to a centralized line will reduce player agency + goal-setting and result in a less satisfying gameplay experience.
On the first concern, the vast majority of oil rerolls come about simply due to bad socket counts so even if oil of luck rng has now been mitigated, we still have to deal with socket counts between 1 and 5 (for 6 socket items) that make the item bad. With nothing written that addresses this and the limit of 1 oil per item, this now necessitates a huge amount of collecting base items to check for sockets and stats and then discard. For example, i usually have ancient armor (sacred) on my drop notifier and then when I get one, I can remove it because I can craft it into the best runeword base it can be. Now, I will basically never be able to remove it from the notifier and I'll constantly be picking up these base items to see if they rolled well which in my opinion is grindy and unsatisfying compared to crafting the perfect version. The current crafting method is focused and goal-oriented, I have a threshold of stats that I'll be satisfied with then when I get them, I can use the item and not worry about it anymore, but with this change it sounds like I'll be fishing for base sacred armors, crowns, gauntlets, greaves, etc. basically forever always checking to see if there are iterative improvements to my current gear which interrupts normal gameplay much more heavily than the focused crafting that currently exists. I personally see this as a regression to a more base unmodded D2 method of doing things where the loot grind ruled all, I really liked that median added methods to reduce loot rng in the way of crafting (baalspawns, rw-rerolling, oil-rerolling, shrines), but now 3/4 of these rng-mitigating features are gone.
This brings me to my next point about concern #1, that this change may increase repetitive cube tasks instead of decrease it. Now that RWs can no longer be unsocketed, jewels are unreclaimable. So if you have an iterative improvement available for a base item, you now have to remake all included jewels which is a potentially huge repetitive cube grind depending on your personal threshold for an acceptable jewel. This is inherently unsatisfying since you are essentially attempting to re-make jewels that you already made but were obliterated due to this change. Crafting the perfect jewel was quite satisfying, but now that jewels are basically consumable and can be lost, I'll be settling for less and have no particular attachment to any that I make.
On the second concern, I claim that consolidating runes to a single line reduces player agency. In the current version of the game, if you have an elemental runeword that you want to make, you have to make the conscious effort to go run Teganze in order to get it. You set a clear goal, take steps to complete it, and then eventually you complete your goal. I see this goal-setting activity as intrinsically satisfying. In the OP, it is written that we are now *always* grinding for runes, which I read as we are now simply praying to rng-gods that we get good rune drops. No more setting goals, no more focused gameplay, just pray that you get the runes you want. I see this as a downgrade.
To wrap up, I feel these changes are regressive, "returning to monke" so to speak and remove some of the improvements median made over the base game. I hope that these speculations will prove to be incorrect when this update happens. And don't get me wrong, I agree with the intention, it just feels like these changes may not bring about the intended result. I am happy that Torajan great runes are getting removed though, that place sucks.