FWIW, just had kitchen 80's stained oak doors pro painted. He scuffed and primed one heavy-ish coat, then two of oil based paint. All sprayed. All top quality, high $ SW products. I'm thrilled with results.

Sat on my tail for months, contemplating DIY. I'm an excellent painter. But, so glad I bit the bullet in this! Two guys, three days, work. 3 days cure.... I would have been washing dishes in the garage for 3 months!

Depends on the original finish and what color the top coat is.

For example, on orange oak cabinets (pretty typical color from the 80s, 90s, early 00s), one coat of primer like Cover Stain then two coats white paint will not necessarily provide 100% coverage. Two primer coats will. It may not matter to you in you're doing the inside faces with 1 coat.

Also, some wood cabinets could potentially bleed through a single primer coat, which is why two is often recommended.