The 13th amendment was already passed by Congress when Lincoln proposed this resolution. Said amendment rendered questions of compensation and 4th Amendment issues moot. Unless, of course, Lincoln believed the Amendment's ratification was in doubt. I guess that's not impossible considering that Lincoln's re-admission policy was much more lenient. Without Southern states being compelled to ratify as a condition of re-admission, the 13th Amendment would not have been ratified when it was. So maybe he was hedging his bet on the legalities of the emancipation issue? Possible.