Precioussoul

They might ask, but with a reasonable explanation (like you have), it won't hurt it in any way. You are far form the first couple to abandon the K-1 process and go for a CR-1 visa.
 
If he enters on the spousal visa after the 2 year anniversary of the marriage (it's not based on when the visa is issued), he won't need to go through ROC.
The timeline for a spousal visa is ~11-15+ months on average last I checked (likely on the longer side as Montreal is backlogged).

To avoid leaving and loose ends should the two of you choose to withdraw at this time, suggest that both of you be sure to write explanatory letters, with DOS casefile number and USCIS receipt number to the Montreal consulate and to the USCIS service center that approved the F-129F visa petition.

I submitted paystubs and a letter from my employer with professional letterhead and a signature. If your interview is after the next fiscal year starts but you haven't gotten your tax return back yet, you can always submit a copy of the form you filed in place of a return transcript. Just be sure to submit the W2s with this. 
 
Good luck!

We submitted tax transcripts and letter from the employer stating the start date and annual salary.
 
If the K1 interview takes place after 01/01/2020 you should be good as you'll have tax docs by then. You don't have to submit anything when you file the petition, only the beneficiary needs to bring the documents and Affidavit of support to the interview. I had all needed but the CO only asked for the affidavit of support.

5-6 most current paystubs, and/or ask your employer to provide a letter stating your current income