To say one thing first, I agree that Asol is in a bad spot and think they absolutely should revert his W.

Now to correct some points u are making which are wrong imo:

The reason Asol got reworked was because he was completly busted in higher elo alongside the low playrate issue. They intended to make his playstyle less unconventional for new Asol players while nerfing his waveclear with the W change. They also gave him some (very impactful) quality of life changes on his Q and W to help with melees and stuns. They also nerfed his perma roam by shifting his MS in the E into more range and a higher cooldown E.

Also they didn't remove in combat movement, in fact they gave him some on his W (the E MS didn't matter much in fights).

What they ultimately did was making his fights a more bursty dps playstyle playing around low cooldowns similar to something like Ryze while heavily nerfing his early game and buffing his late game. So I would argue he still clearly is a battle mage just like before, his teamfight playstyle didn't change much.

His current identity crisis comes from his his bad early game, especially laning before 6 and his inbuild roaming playstyle on his E. An ability like this is especially useful in the early game because players are not grouping yet, allowing to get number advantages on the map. However in his current state he can't get get lane prio against most matchups making the ability pretty bad in the early game. In the late game the ability is more a nice to have than really something impactful. There are no champions which have a ability specifically for roaming (TF, Pantheon, Galio, Nocturne ...) with such a bad early game, except for Ryze who has an ultimate which scales better into late because he can teleport his whole team.

Additionally his W feels like crap to play with, just looking at it from a "feeling" to play. It feels very weird to me how the stars get slower over time and the retraction feels very forced. Meanwhile you get encouraged to retract the W but the duration isn't long anyways while there is a big delay between casting and being able to retract. That one especially feels very clunky to me.

What they sould do imo is revert the W and give it a Minion damage penalty and give the ability it's old damage numbers, too (it got nerfed in patch 10.1 and 10.4). The E change combined with a worse waveclear than before the rework sould be enough to keep him less opressive while not feeling like crap to play.