When Ryanair put routes on sale the day after they announce them that dosn't mean they will stay at that time. Over the next few days they will have to change the Porto timetable. If the route is to be operated from another base it will be most lightly be from the Dublin Based aircraft.
I think a Base in LGW is not to far away either. A while back Ryanair said they would move rotues from LSTN to LGW and they have.