Hi @Wacky1.nash,I am moving to the US on a greencard (immigrant visa) mid next month. I applied for citizenship on Oct 31, 2021.
I called IRCC about 9 months ago and asked if this would pose any issues with my citizenship application, and the response was, "No, it wouldn't so long as you meet the eligibility criteria." Intent to reside in Canada after receiving citizenship has been removed as a criteria for becoming a citizen. So moving to the US in itself does not lead to denial of your citizenship application.
The IRCC agent did tell me, they might scrutinise my application more than usual. I expect this would translate into delays in processing (although when i asked her if it would mean delays, she said not necessarily.)
The biggest challenge I think is just ensuring you meet the Residency obligation (730 days of physical presence in Canada within the last 5 years as of the day of your oath), and are able to travel to Canada for test and oath. As for communication from IRCC, it is mostly over email, but you can also update a US address with them to send you any communication (US is the only other country besides Canada for which they accept communication address.)
The IRCC agent was very friendly and seem to perceive the move as negative at all. In fact she congratulated me on it and wished me luck.
1) Your citizenship application may be scrutinized more because you are going to the US as a PR whereas the original question was about going to the US to work - non-immigrant visa.
2) For Citizenship 1095 days of physical presence required - not 730 days.
3) 1095 days in the last 5 years as of the day you sign the Citizenship Application - NOT as of the day of your oath.
4) These days both the Test and Oath can be taken online - Outside of Canada
Thanks,