Consider this a personal gripe: I firmly believe Shen should have received the honor of an Ultimate skin. If they declare MF as the only top tier skin for the next three seasons, I really don't have faith in the creative team.
Now, does this mean he will never get one? Of course not. However, the pattern which we thought Riot was abiding by has been shattered. There is no telling when he might get it. Now, any member of the old cast is eligible for one of these brand of Ultimate skins. Hell, we may well see another five years and a rework before Shen is allowed to have an Ultimate.
Riot and Anna were kind enough to tell us that they finally have a long-overdue Shen skin in the works, but as it stands, it's pretty much confirmed to not be an Ultimate skin. So, the several year long wait was essentially forced upon Shen players because other champions with tits and asses were selling too good; integrity and vision can take a backseat to profits.
The entire point of distinguishing GGMF from the rest of the Ultimates is to not allow what could be a future feature (for free) to be bought for $25 now. Remember when they patched Champion portraits to match the skin you were using? You had to pay for that shit before, and you could only do it on four people.
Now every champion has that courtesy, and Ultimate skins have the unique privilege of using custom map icons.
The entire point is to get your money's worth when it come to shelling out almost 30 bucks for a skin for one of your favorite characters. The only reasonable uproar around Spirit Guard Udyr I could find is the argument that it thematically changes nothing about his kit or appearance, only makes them what they were supposed to be from the start. SGU is just vanilla Udyr, with 100x better effects, and as a result, Riot have neglected to even give Udyr's base model a VU, despite it being one of the worst offenders of clunkiness.
Urgot is technically the champion to go longest without a skin, but with his rework being somewhat recent, and the rising demands for Star Guardian Urgot, his players will be at least somewhat satiated. He, rightly, didn't fit into many skin lines.
Shen, however, is eligible to be one of the best fucking blank canvases for the following lines: Star Guardian, World Breaker, Heartseeker, Warring Kingdoms, Dark Star, Pool Party, Academy, Totally-Not, and of course, PROJECT.
Since they decided to skip over Shen for so many obviously phenomenal choices, I just prayed they were using every stitch of effort to make a bitchin' Ultimate skin. I am almost certainly wrong, as you can see. But I'm just a hopeful nerd with a one-trick he loves. My biggest worry is that Riot will dump this one Shen skin, and wipe their hands clean of him again for as long as humanly possible. If it were an Ultimate skin, it could be acceptable, but now it's just the given norm.