Constructive receipt means that the check was able to be obtained by the recipient. With both the check and the Form 1099-R going to an old address, it seems unlikely that there would have been constructive receipt, although I don't think that that would have precluded this from being a distribution made in 2016. (What it lack of constructive receipt in 2016 might have done is to have allowed the funds to be rolled over upon receipt of the replacement check, but that probably would made no sense since it's too late to recover the tax withholding.)
