They rightly fear that in 2-3 years, when the pandemic is likely over everywhere and other people have figured out how to commercialize the IP, they won't be the only ones producing their vaccines.

This isn't going to help India or anyone in the short term and there'll be more than enough doses for every person on Earth by next year. Why should they not retain the IP rights to make a profit on new generations that need to be vaccinated or potential booster shots? The manufacturing capacity will have been built up so scarcity won't be a problem at that point.