I've now read several studies about successful long term weight loss maintenance. And none of them mention speed of weight loss as a factor. The Wikipedia article on it doesn't mention it.

Also here's a study that suggests the exact opposite, that rapid weight loss is correlated with long term success.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3780395/

The system definitely experiences hysteresis.(if you drop and regain weight you're metabolism will be slower) But I haven't seen any evidence that the rate of weight loss has any influence on it. I can see the intuitive appeal, but I haven't seen theoretical, epidemiological, or any other empirical evidence for it.