I have a pond thats about 50`X200` and around 15` deep at its deepest. I've been watching a video on a homeade deicer and I thought it would be easy to build and power with a solar panel, since theres no power there. I was wondering if using the deicer to make its hole in the ice would work to keep the fish alive insted of aerating? Below is the video links.

Here is the deicer overveiw:
https://youtu.be/OxrmbUkMihk

Sorry there are 9 parts to the build, this is extra:
https://youtu.be/O_DxgN7OByA

The hole he has open will not do any good(extremely little good) in my opinion.

You need water to air interaction to see the benefits. Keeping his hole under a lid defeats the purpose of having a hole open. Also, that size hole is of very limited use.

Do it right, or don't bother.

That said, there are more efficient ways to keep a hole open during the winter. A small air pump with a single defuser can do a lot more good than most think. Start out small and add if you must. Understand your pond. Its location, the temps you will see and for how long, how much sun do you get, location, location, location, ect.

Moving air is the cheepest way.

do you have a creek feeding your pond in the winter?

No creek feeds the pond. Fish winter kill in the pond with without aeration. Yeah the video made it sound like the rubber tub would work on its own, but it makes more sense to just aerate.