[x]

I wonder if the estate actually owns the copyright still.

I think they do:

Harrisongs wikipedia article.

Harrison's earlier songs for the Beatles are part of the Northern Songs package that Michael Jackson owned for a while, but Harrison hated the Northern Songs contract and set up his own publishing rights company before writing and recording songs like "Here Comes the Sun" with the Beatles.

[Fhios]

Well, the rumors that Paul McCartney wrote the wong for him ... made me wonder.

Music Licensing is weird. I think all the large Venues buy ‘play rights’ from the RIAA