2000 words a month is too less from a blogging perspective. Also, if they wanted to wait for the volatility to settle, they could have updated your exiting blog posts, optimized your page speed, and built backlinks.

Also, what about future Google updates? They push out at least 1-2 core updates and many smaller updates every year, do they plan to keep a hold every time?

I can’t think of any of my clients who would agree to this. This is because good SEO cushions a website against Google Algorithms, sure there are fluctuations, but the rankings restore within a week.