I would recommend issuing them.
It is required for a "Trade or Business". In SOME cases, rental properties can be a "Trade or Business". The Tax Court has even ruled that in some cases even one rental property could be a "Trade or Business".
In the past, for most things it didn't really matter much if a rental was classified as a "Trade or Business" or not. However, starting in 2018, rentals that qualify as a "Trade or Business" can potentially qualify for the new 20% §199A deduction (if all other qualifications are met). So now it is highly desired to for the rental to be classified as a "Trade or Business", and filing 1099s could support that.
