Call it conspiracy theory but i have a feeling this was a strategic WD, after the not so great SP result.
There were realistic chances Tuktamysheva would have beated Medvedeva, and they probably didn't want that to happen. Anyway Medvedeva's chances to make the team were basically none.
The approach kinda reminds me of Post 2010 Olympics Yuna Kim: show up only at the events she is sure to get something out of it.
They probably want to have a very strong first half of the season, winning as much as possible to go to Nationals as one of the top 2-3 skaters, with maybe a GPF medal and make a case to be in the team, and they understand they might need a quad for that, or even just saying it makes you willing to stay in the top in the eyes of the media/public.
I love how Perviy Kanal is so on top of the drama, they had the Eteri cam when the speaker announced it, trying so hard to capture a reaction (that supposed eye roll)
I don't think this was a strategic WD in the sense that it was planned to happen - her boot broke at competition practice prior to the SP. The only way it can 'strategic' is if somebody from TCC breaks rank and says that she knew her boot was in poor condition prior to her going to Nationals - which I don't think this is the case just stating the only way this comes out as a 'planned' action.
I hate to say it, but I agree with TSL a bit - this was really the best outcome for Medvedeva outside of 2 of the trio of Shcherbakova/Kostornaia/Trusova having disastrous enough competitions that put her on the podium. She got to have a good showing in the SP and WD not for an injury and didn't go out and have a subpar or even great skate and finish below Shcherbakova/Kostornaia/Trusova to further demonstrate how far below her competition her technical abilities are.
In reality she knew that it was unlikely she get on the European/Worlds team, otherwise she wouldn't have signed up to headline a skating show that's in Russia (her coaching team is in Canada) during training time for Europeans.