Future upgrade included in the plan?

im thinking buying gtp4-0 for a year, but what if gpt-5 comes out during that year, will my purchase automatically upgrade to gpt-5 or will i have to buy again?

Hey, you get access to GPT-4 with the + subscription. I would assume that once GPT-5 becomes widely available, all plus subscribers would get access, but there is no way of knowing for sure.

thus the question, but its a fair one