Does the Typhon Pact have anything to do with the Typhon Expanse from Enterprise (I hope that's not a too dumb of a question to ask)?
The Typhon Expanse is actually from TNG; it's where the Enterprise
were trapped in a time loop in "Cause and Effect." You seem to be confusing it with the Delphic Expanse from the third season of Enterprise
Typhon was a mighty monster from Greek mythology, kind of a multi-headed dragon that battled Zeus for rule of the universe. He was the father of many of the worst beasties of Greek myth, including the Hydra, and after Zeus defeated him and flung him down below the Earth, his upheavals became the cause of earthquakes and volcanoes. Presumably the Typhon Expanse was named in his honor, and the name "Typhon Pact" refers to a treaty signed somewhere in the Expanse (like the Warsaw Pact it's based on; the treaty that founded it was signed in Warsaw, Poland).