Yes in 2 ways:
- Gradually through the years, so slowly they don't even notice it
- If they internally decide they have to do it, for some motivation of their own
What will never ever happen is that people change if others demand it from them. If you hear someone saying "I promise I will change" - no they won't.
I don't understand the resistance to changing platforms that many people and especially companies show.
For example the company I work for refuses to consider anything except Xitter. Casually talking with the people running social media, I concluded they think about platforms as a fixed fact of nature, rather than something flexible that you can experiment with.
There's basically a minimal cost to having a multi-platform presence. Copy/paste your posts to 3 places, there are even tools to automate it.