Can bracers let go of the top person during a braced flip?

Yes, once the top person is coming down, under Rule 2-3-5d (new for 2026-27):

If the flip ends in a cradle, a horizontal position at prep level or below, or on the performing surface, the bracers may release the top person or move to a loading position once the top person begins to descend.

Hand-to-foot connections: after confusion about the new hand-to-foot braced flip, NFHS and USA Cheer issued an official clarification. A bracer holding a hand-to-foot connection may also drop to a loading position or release the top person's foot when the top person is landing in a horizontal position or on the landing surface, as described above. Situation 2.3.5.F and the photo example on page 67 of the 2026-27 rules book are correct.