Technically yes. As very simple and obvious example, if anything significant has changed that makes the sponsor/applicant ineligible (eg a sponsor now not a citizen or PR or PR not residing in Canada, etc); or, again, rather obviously, if something is discovered that disqualifies either that was not known or considered before (criminal history discovered?).
I do not know but doubt that it could be refused on the same basis as before (unless, again, something changed/new information comes to light, like couple divorced).
This may sound trivial but it's not: it really is starting the whole process all over again (for the most part) since the same obligations on IRCC (the visa officer) to check and be certain of and document all the things that are required under legislation. If they need to check the sponsor is not on social assistance, that starts over.
[Note: I am not trying to defend IRCC's processing of cases under appeal - nor saying that this is done 'quickly' or with sufficient care or fairly or whatever; no moral/subjective judgment or approval from me whatsoever. Just noting that IRCC's responsibilities under legislation don't change because it's an appeal, and since they treat the process as starting over (which in and of itself may not be fair or justified - no opinion), they re-do many verifications and complete verifications that weren't done before.]
