These signs were put up in light of the announcement the other day of Aryeh Deri's return to politics and his intention to head a political party.

I figure like this:
If they were put up by Aryeh Deri supporters from outside of Shas, they would not want him to head the Shas party, but a new independent party. It makes sense, to me, that these are supporters of Aryeh Deri from within Shas. And that they are saying "the majority determines and not the rav" that looks like the beginning of a rebellion...

of course another option is that Aryeh Deri put them up himself and perhaps he himself wants to be head of the Shas party..