I'm guessing the main intention of this rule may be to allow teams with trans/non-binary members (like Cain/LeDuc) to have their gender identities officially recognised in competition. Timothy is acknowledged as non-binary such by fans, but the official definition of a pairs team meant they technically competed as a man, so this rule would have fixed that technicality for them.
I agree that the physics of required pairs elements mean that a cisgender team will likely not be competitive at the highest level against conventional teams unless they are male with an Uno/Memola height difference (or Jean-Luc Baker/Brandon Frazier, who've posted footage of a headbanger lift for fun). At least one member of the team needs to have gone through puberty with high levels of testosterone in order to have the upper body strength required for overhead lifts (hence why young pairs boys can't do these lifts). In ice dance, at the lower levels an all-female team might manage with synchro-style lifts, but the requirements for level 4 lifts are also not realistically achievable compared to men.
I can certainly see cisgender female ice dance being embraced at the grassroots level (e.g. StarSkate) because it's either pattern dance or a free dance with limited lifts. Varsity skating events include dance couples and fours. There is no gender requirement but due to the demographic of most varsity skaters, most teams at these events are female. They skate shadow only (same steps) at least in Ontario. I think partnered is perfectly feasible though - some patterns have very similar steps for both partners.