People are going to lose their mind if they change the main logo. It doesn't matter if it's an upgrade.
I think they need to come up with something entirely new for an alternate jersey. It's been a while since they tried anything new with the brand. The last time being when they very successfully rebooted the O.
I posted this in a previous thread, but I think a logo with a Lion is the way to go. It's already associated with our team because of it being a part of the (historically not accurate) Roman coliseum design theme we have going. Our mascot is also a lion, so it isn't a stretch.
I also think we need to buy the rights to Lenny The Lynx, but that's an entirely different discussion.