I think the issue is what is considered the default and many smaller museums, at least, still seem to have a default of no photography so if the artist or lender does not specify otherwise it will be assumed photography is not allowed. This has to change before a museum will decide that photography is a policy they will mandate for artists.
AR in the museum space seems like interesting means of questioning institutional authority.
Other issue of AR artworks in the museum is that due to copyrights some institutions simply ban mobile devices so if an artist showing at the museum has an AR work a means of permitting mobile devices in the museum space must be negotiated. Becomes more complicated if that AR artwork is not officially recognized/invited by museum.
But it's often done without a consciousness of that difference and that is what is problematic now. We no longer have an awareness of the physicality of the infrastructure that supports the digital which causes us to take its presence and functioning a it too much for granted.
Seems one of biggest hurdles to allowing photography in museum is not so much the museum's understanding of media or issues of control of visitors, but rather getting lenders to understand and accept the public's desire to photograph...
AR is great but difficult conservation-wise. Made an AR piece and three months later the platform changed its format so it no longer works. Now it only exists in documentation much like a performance. There is an issue of ephemeral and temporality in this medium.