You misidentified the fallacy - it is the fallacy of the excluded middle. Only two choices are given - "Jesus" or atheism. Clearly many more exist - QED.

If all religious people believed in exactly the same religious beliefs, beliefs which they had come to independently, this might be a good argument for theism. This is one of the arguments for science being true.

Conversely, the fact that there are dozens of major religions and thousands of Gods over history is an argument against theism.

Good article overall, have claps!