Well, it sure did put on a show!* Since it's not a threat to people or a structure you can consider leaving it to see how it does.* Trees are sometimes a surprise to me in their desire to live.* Crabapples tend to be tough trees in situations like this.*
" when trees are threatened with impending death, they will often put out a profuse amount of fruit. "
"Does that include a profuse amount of flowers, too?"
Yup, the flowers come first, then the fruit.*
"I did read somewhere that the flowering crabapples will only bloom profusely every other year?"
That's called a "mast cycle." Trees of a given species (or closely related) will all have a heavy seed production year at once. It's thought that this may be an adaptation to overwhelm the seed-feeders with more food than they can possibly eat, so that a greater number of the seeds will survive and germinate.* Of course the seed is in the fruit.
Newt
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant.