Or somebody did some math and figured out having corp clients have elite status simply caused them to buy more tickets on UA, so it's worth giving the status to them.
Or pegging mileage earnings to ticket price plus revoking elite benefits for award travel purchased for others changed the dynamic enough that this made financial sense.
Giving out elite status doesn't really cost United much except the increased RDM. RPUs just change the order of who gets CPUs; GPUs might arguably drive more revenue through higher fare purchases to use C seats that would have otherwise gone to non-revs, and UA "loses" ancillary revenue like E+ or bag fees or SDC fees that they don't get if they're not selling the tickets in the first place.
And elites who don't fly don't really cost UA much of anything... so it's really just a matter of whether over those extra 10 months of elite status UA loses revenue because flyers don't buy more tickets to keep status, or gain revenue because flyers keep buying tickets because they have status....