There is a symplectic tag on MO that currently contains just two questions. The first question so tagged dates from March 26 2017, so this makes this tag at least 1 year and 4 months old. I believe that this usage frequence shows that the tag is not really needed. I suggest to remove it and retag the two questions with sg.symplectic-geometry. It is hard to imagine a case covered by the former but not by the latter tag.