They had good reason to be concerned.
Do you think a boa eats weekly in nature? Compound that with captive bred, fatty prey that we feed and you have a disaster in the making unless you don't care if your boa, which is very capable of living beyond 20 years, will die off early.
Manifestation of fat in a boa isn't something you'd catch externally unless it was too late.
I'm not sure why folks miss out on the book Vincent Russo wrote, THE COMPLETE BOA CONSTRICTOR but the book does explain the diet of boas. Mick Mutton and Vin also spoke of over feeding in captivity on a podcast show. Grab a copy of the book if you don't have one. You will be happy you did.
Gus Rentfro, who is a world authority on boa constrictors states that it is "Entirely to east to over feed a boa, but almost impossible to under feed one."
A large rat every 21 days to a month is plenty for an adult boa constrictor.
In my opinion, mixing up the frequency of feeding and the prey type and size is the best way to go.
I don't feed my boa from Late October until late March or early April. Yet still he grows. Maybe even more-so when he doesn't eat.
You have to think about what reptiles were designed to do. They are extremely efficient and capable of going long periods without food, and our keeping disrupts their natural cycle no matter how hard we try to provide the proper elements. This whole topic is much more complex than a feeding schedule.
There is simply no reason to feed and adult boa weekly. I'd even state that almost NO snake, other than a young, developing animal needs weekly feedings.
Think long term, as in 20 plus years.
If you are specifically asking about boas, you will not hear an intelligent, well researched boa keeper ever talk about weekly feeding an adult boa.