https://www.canada.ca/en/immigration-refugees-citizenship/news/notices/application-kit-spousal-sponsorship.htmlThank you, I'd still like to find a source for this grace period!
Ottawa, February 14, 2018 – Family reunification is a key immigration priority for the Government of Canada, and we continue to improve our processes and procedures to help families reunite in Canada more quickly and easily.
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If you have been filling out an application using the previous version of the checklists (identified in the bottom left hand corner by version code 10-2017), we will still accept your application using that previous version until March 15, 2018. However, we encourage you to use the new checklist, guides and processes right away.