It might be enlightening for some to look at what happens to someone who builds a house on land they don't own, and then lives there for 30 years. It's a pretty well established body of law.
Also a tenant in your situation would most certainly have rights to not be "unceremoniously kicked out" - both a time period before they'd even be legally expected to leave, and also legal protections against being forcibly removed even if they didn't leave at that time.