I think this is altering the initial logic and when validation happens. I would prefer it if we kept the logic of how we validate the deprecated fields similar to how it used to be, and keep it in class PipelineTask: the way I suggest doing this is:

Return these fields as float types, but rename them as:

    cpu_request_deprecated: Optional[float] = None
    cpu_limit_deprecated: Optional[float] = None
    memory_request_deprecated: Optional[float] = None
    memory_limit_deprecated: Optional[float] = None

Then move validate_cpu_request_limit_to_float & validate_memory_request_limit_to_float back in to pipeline_task.py, and when set_cpu_request, set_cpu_limit, set_memory_request, set_memory_limit is called, we set the deprecated fields the same as we did before the breaking change, and validate right before assignment. This keeps the logic functioning similarly as it used to, and it keeps all the logic close to gether so it's easier to remove it when we sunset these fields.

I only followed the way it's done for Accelerator fields. So Accelerator should be changed as well?

The suggestion is to update the non accelerator fields and re-add them as deprecated values to resourcespec

Thinking more on this, I don't feel very strongly about this. @chensun do you have a preference here?

If not then this lgtm.