As mentioned before, folks have made the fundamental error of assuming interventions are going to be necessarily kinetic on the part of the 3 parties to the Mecca agreement. I think other options are available and that is the route Pakistan is most likely to assist with, rather than direct troop deployment to a front line that is NOT actually in Saudi Arabia but is in Yemen between factions in a civil war.
Pakistan doesn't need to, nor is really justified to, get involved in all and sundry "proxy" conflicts around the world (admittedly a bit of an assumption on my part, as I don't know the precise terms of the arrangement).