Neal accidentally sniffed his underwear, scarring him for life. No straight man would ever forgive this.

dead wrong. if it was goodbye forever, john candy wouldn't have said about steve martin's family "maybe i'll get to meet them sometime"

Having just rewatched it over Thanksgiving, it was definitely a good bye forever. Certainly from Neal's point of view.
Hence why they didn't exchange information.
So many stories, so little time.

I am beginning to wonder if you just saw Uncle Buck.

Dead wrong. They wouldn’t have had a tearful embrace if they didn’t want to see each other again

You keep ****ting the bed on this one.
Neil didn't want to see him ever again. It was only when he put the pieces together on his subway ride home and realized that Del was alone, did he rush back to him at the station.

Dead wrong. I've seen the movie approximately a thousand times. If he never wanted to see him again, he wouldn't have given him a heartfelt, teary-eyed hug when he parted at the end.

Just saw the movie the other night. Neil never wanted to see Del ever again.

Dead wrong. I think they did intend to see each other again, because john candy says “maybe I’ll get to meet your family some day.”

No, they didn't plan to see each other again.