I thought at this point they'd decided no more Saints Row games in the current vein, implying not a reboot but something different but in the same design.
Also, remember, the engine while good is designed around the limitations of last-gen console hardware. It needs a hefty update, and considering every mention of bigger memory caps giving them more space to expand into results in someone from Volition saying they'd just pack it full of new features and be stuck again.. they probably have a BIG list of stuff they want to add to the engine first.
Along with that I'll bet they have a number of plans to go with that engine.. right now they're probably focused on upcoming DLCs, notably those story ones that are gonna involve a lot more work to put together from the whole group, but it'd be crazy to think they didn't have a list of "Wouldn't it be cool if---" they shelved, to go with their "Man, if only the engine would handle---" list. It's probably too early to look at a new game right after they released the other and they have DLC to make (moreso, presold thanks to the season pass)... but it'll come and they know there's thought to be done. They might not make another SR2, but I already HAVE SR2. I don't need another, I want something like it, and I suspect they know that and have already done idle pondering. I'm not gonna worry about them 'rushing' anything, not for a long while. (Of course, if they release a 'final dlc' and then announce they're working on SR: Redux with a release of the next year, THEN I'd worry.)