Yes I saw that on Flightradar and Flightaware, unclear why they chose 8190, but I'm told everything internally still reflected the tail N27270 flying as 2297 - 04 EWR-LAS, including on united.com where UA8190 pulls up nothing for flight status but 2297 does pull up the EWR-LAS segment (even though it doesn't on Flightaware/Radar) and shows tail #7270. Likely they just needed an open number to give ATC to prevent confusion without needing to cancel/move over all passengers from formally changing the number.internally. The 8015-8714 block is normally used for UA codeshares operated by AC (and their regional flying partners). The 3010-3049 range is for extra sections, however this wasn't really an extra section - it was a normally scheduled flight that had a conflicting flight number. As far as I can tell there is no formal flight number block reserved for this type of situation where the first segment of a change of gauge causes a conflict with the second segment. Just another example of the problems with change of gauge flight numbering and more reason to get rid of this practice IMO, but I'm sure airlines have their reasons for keeping the archaic practice that even their system struggles with.