For BOOST_PHOENIX_NO_VARIADIC_EXPRESSION I would say yes, since I am not sure anything has changed on that front since this thread Stan-dev/stan branch develop throwing compile errors
We are now using Boost 1.69 but I dont think that makes a difference.
For BOOST_DISABLE_ASSERTS I am guessing this was added because we advise against asserts in the codebase? Cant find any discussion on that, only the commit. Just a guess tho, pinging @syclik