I think you have it a bit turned around, I meant that the ISU will likely allow neutral athletes from Russia and Belarus to return to competition in the Olympic season exactly so that they have a chance at qualifying for the Olympics - on paper.
Why on paper? Well, because the Nebelhorn Trophy is not free for all to enter in the Olympic season and the hosting federation will have the right to make selections if the planned entry number is larger than the entry limit. Apart from that, I'm not sure about the visa situation - If Russians and Belarussians can't enter Germany due to lack of visa, then their chance of qualifying exists only on paper. Neither of these situations would be the fault of the ISU then though, and similar to the FIG, the IOC could not hold them accountable.
Now, why is the Nebelhorn Trophy important? Well, because it has been one of two Olympic qualification events in the last few Olympic cycles. I can't see them allowing the Russians/Belarussians back in time for the next World Championships, which is qualifying event No.1, so the qualifying event in the Olympic season will be their only option if allowed back in time. Simultaneously, this limits the number of Russian/Belarussian entries to one per discipline, and that only if they place high enough at Nebelhorn (not a problem for the women and pairs, probably, but possibly for the men and ice dancers).