I voted 'Maybe' but I actually meant to click 'Yes'.
Luckily I am a Newcastle supporter, so we're very unlikely to ever merge, relocate, or get killed off. However, hypothetically, should it happen in my lifetime, I would remain a League supporter and watch games. I would continue to cheer for Country against City, NSW in Origin, and Australia in test matches. I would still be very much involved with my local WA club as I am now (although by then, I doubt I'd still be a player!), and I'd still attend WA Reds games in whatever competition they'd be in at that time.
I would, however, lose a lot of the passion I have for my sport without my team in it. There is not a chance at all that I would turn to another sport such as AFL, soccer, union, ect. I may be broken-hearted, but I wouldn't be that desperate.