I agree. What you wrote is a very common scenario in single mother households. It's a form of control by the mother. Often not done maliciously or intentionally by her. It just happens.
In general, boys of single mothers who are controlling like that, if they ever want to be their own man, will likely need to break away from her as a individual choice by him ... but's it's usually only done in a rock bottom moment (because they do not realize the unhealthiness of the situation, or how it has affected him, until they get to a bad, bad place ... they fully believe they are on the right path ... and why wouldn't he? he loves his mother and his mother loves him). Separating can be one of the hardest things to do since the mother is his often the only support network. It would probably do boys of single mothers well to reconnect with their father, where ever he is, and to forgive his mother from turning him away from his father. It's very tough to overcome the anger and hate that develops in children in single parent homes (from the void felt by their absence), but it is possible. Then, the boy can turn into the man they were meant to be and can be.
I wish them well and hope it turns out for the best. Hope all boys who didn't have their fathers around growing up are able to forgive and overcome.