I have a Holley 2bbl EFI system on the way for my 235.

I have learned that the intake manifold needs to be heated.

Would having fuel injection help with that and allow me not to heat it?

Heating the manifold helps a small bit with keeping the fuel vaporized in the intake when the engine is cold, and the same with the EFI. That being said, I doubt you'll notice any issues not heating it. The engines still start when bone cold in winter, and after several minutes of running the intake is going to have heat soaking into it from the head.