Characters like Georgia I can stand, they actually have a comic side and serve a purpose. Characters like Burgundy, I don't see the purpose.
- I feel if Ash gets all three, I'm pretty sure two of them will evolve if not three, there's no reason for any of them not to, as none of them that can really be prohibited by marketability.
1. "I feel" = opinion to which you are entitled to, but is just that.
2. Fennekin is extremely cute, hence marketable. Chespin is just like Oshawott, hence marketable. Froakie is an oddball, therefore could be marketable (see Stunfisk). So all could be hindered by their 'marketing value'. Judging by that, none of them would evolve!
The second bolded notion is something that has been attempted in DP and BW. Most notably Chimchar, Buizel and (though wild and not a starter) SG Sandile/Krokorok. Not to mention purposely done backwards in DP: Dawn with Piplup, Kenny with Prinplup and Barry with Empoleon.
Having Chimchar begin on Paul's team did not only set up the plot for DP, but also allowed Ash's team to grow steadily and at their own pace. If Chimchar was going to be on Ash's team from the beginning, Ash would have 5 pokemon to go through quite a bit of the early region and those five would have to compete with eachother for their shine time. Considering how Chimchar was on Paul's team, this left more time for Turtwig in the beginning of DP, and caused for actual plotdevelopment when Chimchar eventually came to Ash's team. The same happened with Buizel. Started on Dawn's team, and got development and characterization from that perspective.This also still left 'breathing room' on Ash's team so that Turtwig and Staravia could shine a bit more before the otter was traded to Ash.
The same happened in Best Wishes with Krokorok. We got to see it travel along with Ash at certain times, eventhough it wasn't captured. This gave the 8 pokemon Ash had already along with him, with some more breathing room for appearances in gyms, before such a strong pokemon would eventually join.
I quite like this set up. And I feel that if Ash hadn't caught Palpitoad at all, then it would've helped Best Wishes even more. Eight pokemon before the fourth gym was just too much to juggle. SEVEN pokemon on the other hand, is just right: If you're entering a gym, then you're team will likely have 2 or 3 that are unlikely to be a good match, with 2 being neutral, and 3 being good picks. The more pokemon, the more likelier you have good picks, this however, likely leads to even the good picks having to sit out regardless: Tranquill not being in the Castelia Gym battle for example, Snivy over Roggenrola in Nimbasa.
So yeah, I can definitely see this 'suspended/looming' capture, or reversed Dawn-situation happening. It would give the group a better development then just slapping on additions at a rabid pace.