Yes, to oppose is pro-userbox 

The proposal has the consequences of,
 doing away with categories of Wikipedians by POV
 preventing the common listing of userboxes in a directory
 preventing userbox templates deemed not of benefit to creating an encyclopaedia, a messy criterion
 preventing userbox templates deemed POV or advocacy, a messy criterion
 the pro UN template and category would likely be deleted

Please read the proposal for more, but, yes, to oppose is pro-userbox.

BTW, I was blocked for telling you (and 43 other UN Wikipedians) this, but one wonders how else you would have learned of this. =)

Tell more people, few know,