So I have a flight from LAX to HNL in November and being a lowly silver had to select an E- seat at booking. However the flight was orignally on a PMCO non-retrofitted 753 so I got an E- seat in the front of the cabin. Now the aircraft has been changed to a retrofitted 753 but I've been given my same seat number which is now E+. Will I loose it or will they honor it?

I'm just worried if I keep it and they don't honor it I'll get relegated to the back of the aircraft, so I'm wondering if I should switch to a more preferable E- seat for now until t-24, rather than assuming they'll let me keep the current seat.