The changes follow a six-month review carried out by technical director Nick Cox, whose recruitment process brought in Dean Rastrick as academy director in June. Working under Rastrick, Carl Darlington has been appointed head of academy coach development, Dave Hughes joins in the newly-created role of head of academy player development, Ben Dickson has been promoted to head of academy recruitment, and Nick Chadwick becomes PDP senior coach and loans programme manager.
With the U21s post gone, that age group now falls under Hughes' broader remit.
Cox explained the thinking behind the overhaul on the club's website.
"We've spent the last six months conducting a strategic review of our academy structure and these changes and appointments are part of that process," he said. "Our focus is on building an outstanding learning environment that is challenging, nurturing and supportive.
"To achieve that, it's essential we identify and empower leaders who can drive standards and create a culture where players and coaches can fulfil their potential.
"Dean's arrival is key to that vision. He arrives with a truly exceptional CV. His extensive experience across respected youth systems - including Norwich City, Tottenham Hotspur, Luton Town, and Derby County - alongside his impactful work with the Premier League's Professional Game Academy Audit Company, gives him incredible insight and expertise in all aspects of player development and driving Academy excellence."
On Tait's exit, Cox added: "I'd like to thank Paul for his passion, dedication, loyalty and commitment during his time at Everton, and everyone at the club wishes him all the very best for the future."
Tait had been a fixture at Finch Farm since 2017, initially in charge of the Under-18s before stepping up to lead the Under-21s and later serving as caretaker of the first team after Frank Lampard's dismissal.
His exit is the standout change of a restructuring process under the Friedkin Group, with further alterations to youth development, medical and sports science departments expected to follow.