absolutely. Unless it was a 744.
The fact that 4 PE->J upgrades came through suggests a nont full J cabin anyway so there was probably the ability to move people to similar seats. Hopefully.
oh just to clarify my feelings on being upgraded vs paid travel my only feeling there was that if it were me, and I'd paid for J and been moved around I'd feel fare more annoyed than if I'd upgraded to J and moved. As I see it, an upgrade is, while not a gift (unless it's complimentary, but I'll assume points), it's something one usually accepts, and if it's last minute, usually doesn't have much of a choice over seats, even if it's a few days prior, your seating allocation may be limited - or more bluntly "be thankful it came through and accept your options" - but that's just the way I feel about it. If however I'd paid a revenue ticket and assigned that seat before upgrade windows opened and all that, then I, personally, would feel more of an entitlement to be upset about being moved (if not consulted). A minor point I know, and just my personal view. Others will vary I'm sure