How can I get wonder animations in multiplayer?
This reddit post says that if you comment out lines 243 to 245 of steam\steamapps\common\Sid Meier's Civilization VI\Base\Assets\UI\Popups\NaturalWonderPopup.lua
it will restore the Natural Wonder cinematic (not the Wonder built however):
-- Because these popup movies lock the engine until complete; disable
-- them if playing in any type of multiplayer game.
-- if GameConfiguration.IsAnyMultiplayer() or GameConfiguration.IsHotseat() then
-- return;
-- end
Although it's listed as untested, there's a comment stating it does work, but can cause an issue in certain circumstances:
There is a problem where if the natural wonder is discovered during the Please Wait phase(like if your scout is following a long distance move order over many turns and encounters the natural wonder after you hit End Turn), it plays the movie but gets stuck because the X button to dismiss the movie is lost behind the Please Wait overlay. This causes the game to soft hang.
Hitting escape usually dismisses pop ups in civ 6, so that might be a workaround.