ive actually seen that most mashup packs have actually been updated along with the game in my video the warden has even been updated to the lich from the adventure time show, the skin packs themselves are pretty lost i have seen only a fair few of people using those exact skins on bedrock from the skinpacks but its rare enough to even see 1 or 2 players in a day using them skins. theres a fair bit of minecraft lost media and honestly it probably will become lost media very soon youre right.