All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad, sallallaahu`alayhi wa sallam, is His slave and messenger.
If this oil or cream is not an insulating layer that prevents water from reaching the skin, then it is not necessary to be removed or rubbed, in which case, the ablution is valid, but if this cream or moisturizer has a "mass" (i.e. is thick) that prevents water from reaching the skin, then it must be removed before ablution so that the water reaches the place that has to be washed.
Allah knows best.