This tag has been created for the Joss Whedon's movie question (and it's also used for one more question regarding this movie), while the question about Michael Keaton's performance is regarding the 1993 Kenneth Branagh's movie.
No, we should not make two crappy tags merely because one tag has to be made crappy due to tag length issues... that being said...
While we don't have consensus on how to award primary tags or what the rules should be for multiple media with the same title, the general decision is one of several options, with varying levels of support:
the version that gets asked about here first should have the un-dated tag
the first version to be produced should get the un-dated tag.
the most recent version to be produced should get the un-dated tag.
all versions get dated once a second version is added.
all film/TV titles get dated... period. (this has issues due to tag character limits as seen here)
The first three options all (as of right now) have negative scores. The last two have positive scores.
This implies that at the least, both should have dated tags... what would potentially be less crappy is much-ado-about-nothing-12 & much-ado-about-nothing-93 which could look like 12th and 93rd sequels but I still think is better than much-ado-about-2012.
Since it's commonly referred to as "Much Ado" that would be another potential option for tagging shorthand but may go too far.