This measure doesn't directly help people who are renting, in the sense that the benefit flows to the people who are buying homes, but it could indirectly help people who are renting to the extent that it increases the supply of homes more generally.
More importantly, a huge relief measure was provided back in 2023, when the government introduced the purpose-built rental rebate, which provided a 100% relief on the GST for purpose-built rentals. That should help spur the construction of more rental properties. Again, more supply generally results in lower rents.