No that may not be correct. Until the assets are retitled in the name of the son, the income from them is reported by the trust. then you have to look to the trust documents to determine what it says regarding distribution of the income earned and corpus
generally, the Trust would contain specific wording as to income and corpus distribution.
here's an example: commencing with the date of my death and during my son's lifetime, Trustee shall(means must) pay all income to my son ................... (if instead of "must" the word was "may" distribution would be at the discretion of the trustee). (income by the way does not include capital gains, that's part of corpus (trust principal) but again there may be provision in the trust or by operation of state law to allow the trustee to distribute capital gains. Trustee may pay such sums from principal as the Trustee determines to be necessary or advisable from time to time for my son's health and support.
the wording for your trust is probably different.
there is another possibility, quite unusual but not impossible, the son is named as the trustee of the trust of which he's the beneficiary. then it would seem that the trust has gone from being the father's grantor trust to being the son's grantor trust.
