It is possible (for some T2’s) yes
I’ve a friend who did, he was initially diagnosed as T2 as he knew I was and told me
he couldn’t get his Hba1c down with Tablets alone, he was then on more than one type of insulin,
however eventually he was back on just Metformin,
now a few years later he’s still classed as a well controlled Diabetic
but keeps a good control through diet alone