Ana Resendez of the Classic WoW Dev team answered my question “Can we expect to see the return of the disenchant button when items are being rolled out?” during the BlizzCon Q&A. She gave the simple answer of “Short answer, yes. We’re planning on doing that in Cataclysm.”
You can find the answer timestamped here: https://www.youtube.com/watch?v=f8zWAPDUTkc&t=2498s