In good old Letsrun fashion everyone assumes the worst and thinks they know what's going on behind the scenes.
Colleen knows what she's doing. She's not an idiot. She has a new coach who she likes much better. Jerry and BTC weren't working out. Yes, they are the most elite training group in the US, but they are adding so much talent and I highly doubt Jerry cares much about female physiology, not unlike Salazar and his reputation with female athletes. Emily and Vanessa are also consistently injured. Jerry trains them into the ground, then somehow these women bounce back in a super short amount of time, then they get injured again. It clearly wasn't working for Colleen.
Colleen is incredibly influential among young girls and in the sport of T&F. Any company can see that marketing value. She's not going with a shoe sponsor. She's going to sign with an unexpected brand trying to make a name in running and probably make twice what Nike offered her.