Could there be additional barriers either from Canada or other countries that might affect you later (including transit countries)? Sure, could be. But would be pure speculation at this point.
I saw this news just now:
https://qz.com/india/2052159/covid-19-vaccine-will-soon-be-mandatory-for-green-card-applicants/
(In short, US to require covid vaccines for green card applicants)
I would seriously note that whatever [lack of] requirements for PR applicants may be now, no-one can say they won't be required in future. Or just as seriously, that not being vaccinated may involve a lot of extra hoops to jump through in order to travel to Canada.
All speculation at this point, and probably there would be a fair number of exemptions and exceptions and possibly differences between types of applicants (eg spousal vs various economic/skills programs), but it's entirely possible - and arguably likely - that at some point they will start making it required for many PR applicants.
Not to mention that the news is that many provinces will soon introduce some type of vaccine-tracking (also known as vaccine passports) that will mean a LOT more restrictions for those unwilling to get vaccinated.
All to say: for those who really, really don't want to get vaccinated (as opposed to having some severe medical reason not to) - it's going to be less and less compatible with moving to and living in Canada.