I would probably forgive it in this context, but I find it really off-putting when modern people say "shall."
For some reason, in a question, it's OK. "Shall I make coffee?" wouldn't bother me. But I have a friend who, on Facebook, writes things like "I shall watch 'Maurice' tonight" and it always makes me roll my eyes.
I think that just makes you a typical American.
At work I keep a copy of Webster's
Concise Dictionary of English Usage (2002) on my bookshelf. Webster has almost 2-1/2 pages on
shall and
will. The article begins:
The old distinction between these words is no longer observed by most people. Shall, which was once considered the only correct form for the expression of the simple future in the first person, has been replaced by will in the speech and writing of most people. ... In a few expressions, shall is the only form ever used and presents no usage problem: Shall we go? Shall I help you? [Shall I make coffee?] To use will in these expressions would change the meaning. [Will I make coffee? Heck, no!] With the exception of these special uses, will is as correct as shall.
The bracketed material in the quotation is my interpolation, of course, but the citation in the Webster for the paragraph I just quoted is "Warriner 1986." That would be the 1986 edition of John E. Warriner,
English Grammar and Composition: Complete Course. "Warriner" is an old, old junior high and high school English textbook that in its original goes back at least as far as 1951. A former colleague, who used to be an English teacher, continued to swear by it as a grammar reference because it's simple, concise, and traditional. She impressed the rest of us on my team here at work so that a few years ago I bought several copies cheap on eBay as Christmas gifts for my team. I have the 1957 edition on my own desk. We need these things here because the "editors," who are computer people and not real editors, want a simple rule for every grammar change we proofreaders make. They won't take our word for it, even though we're supposed to be experts on this stuff.
In speaking I don't bother worrying about the
shall-will distinction, except in such cases as in the examples, but in my writing I still try to observe the traditional difference. I guess you can take me out of 1960s-1970s public school English, but you can't take the 1960s-1970s public school English out of me.

Of course, in speaking, when it comes to something about watching
Maurice tonight, I'm more apt use a a contraction, where you can't tell the difference between
shall and
will.