"shoo be doo" should be defined?

shoo be doo - I would think it ought to only apply to direct references to the phrase (or puns/variations) or the song or animation (which, admittedly, I’m not familiar with to positively recognize references).
Potential overlap with call upon the sea ponies

But, I see it being tagged on pictures that offhand just look like seaponies without any connection that I can tell, eg:

(the last one I’m uncertain about because they are G1 characters and they are singing)

Should-be-remooved?

It should.

Direct reference to the phrase is the most consistent with how we generally tag phrases.