This personally worked for me to gain access to all of the legacy dlcs. I had already had all of the dlc downloaded but it kept saying that I had to buy the legacy bundle.
While on my computer I went to the following link. I then clicked install on my devices and it seemed like every legacy dlc that I already had downloaded had a very small update and then I was able to play the main dlc legacy missions in Hitman 2.
https://www.microsoft.com/en-us/p/hitman-legacy-pack/bp2h94p...