Well, yes and no. The jophola at the end is not actually given its own codepoint[0]. The best analogy I can give is to a ligature in English[1]. The Bengali fonts that you have installed happen to render it as a jophola, the way some fonts happen to render "ff" as "ff" but that's not the same thing as saying that it actually is a jophola (according to the Unicode standard).
The difference between the jophola and an English ligature, though, is English ligatures are purely aesthetic. Typing two "f" characters in a row has the same obvious semantic meaning as the ff ligature, whereas the characters that are required to type a jophola have no obvious semantic, phonetic, or orthographic connection to the jophola.
Author here.
Well, yes and no. The jophola at the end is not actually given its own codepoint[0]. The best analogy I can give is to a ligature in English[1]. The Bengali fonts that you have installed happen to render it as a jophola, the way some fonts happen to render "ff" as "ff" but that's not the same thing as saying that it actually is a jophola (according to the Unicode standard).
The difference between the jophola and an English ligature, though, is English ligatures are purely aesthetic. Typing two "f" characters in a row has the same obvious semantic meaning as the ff ligature, whereas the characters that are required to type a jophola have no obvious semantic, phonetic, or orthographic connection to the jophola.
[0] http://unicode.org/charts/PDF/U0980.pdf
[1] Some fonts will render (e.g.) two "f"s in a row as if they were a ligature, even though it's not a true ff(U+FB00).