I did not know this. Do you know which ones can be shiny?
Serebii's Pokemon Go page on Shiny pokemon available has all the available shinies, which 2nd stages can be found in the wild and which can only be obtained through evolution (and some 3rd form starters). It looks like most that can be shiny when evolved are those that have mega evolutions or variants. What I can find are:
1st gen: venusaur, charizard, blastoise, beedrill, pidgeot, Kanto ratticate, Alolan raichu, golbat, gloom, arcanine, alakazam, slowbro, gengar, Alolan exeggcutor, Alolan marowak, Galarian weezing, seadra, gyarados
2nd gen: togetic, ampharos, espeon, umbreon, steelix, scizor, houndoom
3rd gen: manectric, altaria
(gardevoir, camerupt, banette, glalie, salamance, metagross, and sharpedo should be available later I figure)
4th gen: lopunny, abomasnow, glaceon
(garchomp, gallade, and lucario should be available later)
5th gen: Hisuian braviary
None from gens 6, 7, or 8