Yes they will be allowed to, but make sure to keep abreast of the latest guideline on travel restrictions:
https://www.canada.ca/en/immigration-refugees-citizenship/services/coronavirus-covid19/immigration-applicants.html#approved
"You are
exempt from the current travel restrictions and can come to Canada
if you have a valid COPR and:
- the COPR was issued on or before March 18, 2020 OR
- the COPR was issued after March 18th, 2020 and you are an immediate family member sponsored by a Canadian citizen or permanent resident (note that grandparents are not considered immediate family members and cannot come to Canada at this time) OR
- you’re currently living in the U.S. and will be coming to Canada directly (transiting through the U.S. to Canada doesn’t apply)
To meet the travel restriction exemptions, you must also:
- be coming to Canada to settle permanently (you cannot come to Canada and leave to go live in another country, even if it’s temporary)
- show you’re able to quarantine for 14 days
If you’re travelling by air, you need to pass a health check conducted by the airline before boarding a flight. If you show symptoms of COVID-19, you won’t be allowed to board."