Apart from the technical side of ice dance where Shibutanis might excel (what we cannot say bc they did not show their skating yet) and being away from competitions for a long time the return is a challenge mentally and physically...
I feel like many ppl overestimate the Shibutanis bc of their former political power in USFS. But things have changed. Marina Zueva's team is also not the strong powerhouse it used to be bc that is IAM now. And being back from competition for 7 years is not easy. I don't think judges will forget the past 7 years and just make them top contenders. In ice dance you need to work for your reputation...I dunno how much of the reputation is left after a whole scoring change.
Imo it was partly politics that gave them the Bronze at the Olympics 2018 in a time where there was no clear No 1 US team skill wise. They were not a team constantly in the world medals throughout their career. They were not even US champs in 2018 (Hubbell/Donohue were!)...so even with their political power in USFS back when they were not the best of the best, not even in the US. They profited from the absence of teams and no clear political order after Olympics 2014 (besides P/C dominating since 2014-2015 season) and had to fight to become world medal contenders in 2015-2016. And they placed 2nd 2016, where Worlds was in the US, but still were immediately dropped further down with V/M return in 2016-2017.
So now 7 years later why are ppl acting like they would become Oly champs? They are not V/M who had a track record of being the BEST ice dance team for years.
I don't underestimate them, they will probably kick a current US team from an Olympic spot and place well in ice dance overall (and I am personally not a fan of returning just for the Olympic season), but to place on the Olympic podium after 7 years is not a given just bc they were on the podium in 2018.
Ice dance has become quite interesting with FB/C and Shibsibs in the mix for the Oly season, but atm there is nothing clear as to how this will turn out. If all this makes things more unclear instead of clear how the season will go....