North End’s last visit to Wearside came on a snowy afternoon in March 2018, goals from Sean Maguire and Callum Robinson giving them a 2-0 victory.
Sunderland were relegated that season and have languished in League One since.
Neil, who managed at Deepdale for three years and nine months, took the Sunderland job in February and lost only once in 18 games as they worked their way into the play-offs and then negotiated a way past Sheffield Wednesday in the semi-finals and then beat the Chairboys.
Sunderland are the third club who the Scot has guided to promotion via the play-offs, having done so at Hamilton and Norwich.
"When you come to a club like Sunderland, people love a fallen giant and love to stick the boot in," Neil said.
"It was such a challenge for me to come here because this club has hoovered up managers over the last four years, but I have always had confidence I could go to a big club.
"I'm not the one dancing around, people think I'm miserable but I'm not, I'm content. I'm extremely satisfied I have been able to deliver so much to so many people that it matters to and that for me is the most important thing, because it has been tough for this club for a few years.
"The team-talk today was talking about moments in your career, this is your moment in time, you could be a hero. For Sunderland fans, this team they will be heroes and they will be remembered forever and I'm so, so pleased for them.
"It has been a really good day for us. That is the most pleasing thing for me that you could imagine."
Neil will talk with the Sunderland boardabout the investment needed in the Championship.
He said: “It was easy for me coming here because I felt that with the squad, I could do the job.
“I walked in the door and it was, 'here's the squad, win games'. I said, 'no problem'. When transfer windows up, when you're going up to a new level, it's very different.
“There's got to be work, investment, different facets that can make you competitive.
“If you're doing a job, you want the tools and I'm no different.”
Former North End defender Bailey Wright was in the Sunderland defence, while Aiden McGeady was an unused substitute.
In the Wycombe side was ex-PNE winger Daryl Horgan who was substituted after 55 minutes.
Wycombe boss Gareth Ainsworth, who had three spells as a player with Preston, said: “I am gutted for the boys but I'm going to say we were beaten by the better team. I'm not going to say we were unjustly done.
"They definitely had the spoils early on and got the goal, then the game was very close.
"The second goal really killed it off, that was a sucker punch we took. We have played better than we did here and unfortunately on the big occasion Sunderland were the better team.”