I think your first sentence that one "can't slander the dead" would be highly controversial, especially considering "don't speak ill of the dead" is an English proverb.
I personally believe in that proverb (there may be extremes where it would be okay), and many others do too - or else, it wouldn't have attained its status as one.
Certainly as a matter of law you cannot slander or libel the dead and I definitely consider them fair game for a forthright discussion.
In the case of these two skeletons, so little is known that they are essentially a natural phenomenon; calling them “lovers” is to me no different from calling a geological structure “the old man of the mountain” or the “tooth of time”. Simply a poetic expression.
> You can't slander the dead (who in any case have no rights) so it's OK to call them what you want.
That might be right from a legal point of view in many jurisdictions.
But that's pretty much irrelevant for the discussion at hand.
You can't slander the dead (who in any case have no rights) so it's OK to call them what you want. And poetic names abound, from archeological sites like this, to the species names of insects, to toponyms and beyond.
I consider it harmless. Ideological names are more dangerous.
If someone found useful DNA and determined a parental relationship then it would make sense to change a then misleading popular name to something likely more accurate, but until then...