The cancer continues to grow.
United Express is expanding to Ronald Reagan Washington National Airport next month. Two flights a day are transitioning from mainline to E-170s operated by Shuttle America between Chicago and National.
United has not addressed these changes, but a likely explanation for the shift is the war going on right now between Delta, American, and United on the ORD-LGA route. UA has pulled UX from LGA and is offering hourly mainline service, at least for the next few months. United doesn't have an unlimited source of planes, so the additional mainline aircraft had to come for somewhere.
My opening statement above was made to grab your attention, not out of disgust for this news. To be honest, I'd rather see United Express on shorter flights that do not include meals in first class. I also like the F seats on UX's E-170s very much--they are almost as comfortable as the mainline seats. Sure, there is no channel 9, mainline crews are generally better, there is no proper glassware, and it is always better to be on mainline during irr/ops, but I am not going to stress about these, perhaps temporary, changes.
I do hope that UA has the sense to keep the DCA flights out of the F-Terminal at O'Hare and in the B (preferable) or C Terminal instead.