They aren't required to. See "Exceptions" on page 4 of the instructions (see Exception #1-e).
<a rel="nofollow" target="_blank" href="
https://www.irs.gov/pub/irs-pdf/i1099b.pdf#page=4">https://www.irs.gov/pub/irs-pdf/i1099b.pdf#page=4...>
I think it is crazy (and poor customer service) that you need to specifically ask for a year-end statement rather than them just sending it to you.
