You can continue to use plain Terraform forever. It would only affect you if you use a tool like Env0, spacelift, Gruntwork pipelines, etc instead of something like the Terraform Cloud.

These tools are not going to be able to be used with users using new Terraform versions (though they can always use the current or any previous versions, or can use their fork these companies are jointly supporting).

Then there are open source tools that don't directly compete with Hashicorp that are in a bit of a gray area, but I've seen Atlantis, Pulumi, OTF, and other tools all claim that this does not affect them. I would presume this could also apply to things like Terratest, Terragrunt, etc. but I don't know. I am not a lawyer.

And if none of these company/product names are familiar to you, then you shouldn't have any noticeable difference :)