There are - but none specifically for parents / grandparents.I’ve heard there are some types of LMIA exempt work permits too?
Generally to qualify for an LMIA exempt work permit, you need to have a specialization and be taking up a job in a specific occupation. For example, there are some LMIA exempt options if you are going to be teaching at a university. Sometimes the location where they will be working can also make a difference (e.g. rural Quebec). Another example is if they are going to be working outside of Quebec but the job they are taking is going to be in French (obviously they would need to be fluent in French for this to be possible) and the job is skill level A, B or 0.
Full list of LMIA exemptions are below. Note that they will still need a job offer from an employer in an occupation that qualifies as LMIA exempt. They cannot apply for an open work permit. You'll need to dedicate time to researching what's available that might fit them (and then secure the right job offer to make the work permit possible).
https://www.canada.ca/en/immigration-refugees-citizenship/corporate/publications-manuals/operational-bulletins-manuals/temporary-residents/foreign-workers/exemption-codes.html