It will not be a guarantee if a dice sites has no house edge then the gambler will be able to profit from since in the end it will depends on luck itself.
Playing in a site with no house edge itself will be an advantages for the gambler itself but the house usually lower the house edge in term of bonuses which of course will be obtained for X requirement


I would say it will be easier to make a profit but still not a guarantee. If you check at this site (unfortunately it has been closed) https://bitcointalk.org/index.php?topic=1024221.0. The house is on negative house edge due to the recover loss function. In the end the site is closed since I thought it is not profitable for the house or neither the investor

P.S : OP of the site claimed that it is not that the site is not profitable but I think it is because of that