interesting article. but the writer seems too obsessed on "conspiracy" and downplays the effect of sanskrit. while farsi had a major influence, sanskrit still remains the source and mother language of bangla. noticed it is from religious site and thus trying to discount sanskrit (and hindu) influence. thus I would be wary of his motive.
he claims the very word "bangla" is persian derived. that is up for debate. during the roman empire, this region was known as "vanga" and over the years changed and morphed into bangla (or bangala).
nevertheless, after sanskirt, farsi had the most influence forming bengali.