Well, the next question to answer is, should the package without active upstream maintenance be the reason for slowing down the progress of another project? Should such a package remain in Fedora at all?
I would personally avoid to do such openexr2 package split, just because I know how painful it will become to get rid of such versions later from Fedora and do it just as transition never worked for me - it remained in the compose for much longer than expected, but it's just my 0.02$.
Best regards
Josef Ridky
Senior Software Engineer
Core Services Team
Red Hat Czech, s.r.o.