Al and Cu in the same fab is not exactly what you want in the first place. There might be compelling reasons to do it anyway.
Yes there is and aluminum will likely be used again for local interconnect (i.e. lowermost metal layers) as process feature size shrinks.
The problem is the barrier layer for copper doesn't scale down as fast as metal minimum width and spacing. This means as copper wires scale down their resistance goes up faster than basic dimensions would dictate because their copper core is less and less of the total wire. For very small wires this closes the conductivity gap with aluminum. The lowest metal layers have the tightest geometries so it is where copper loses its effectiveness fastest.
The intermediate (middle level) and global (upper) wires will still be copper because of lower RC delay and much better ability to carry high current reliably.
That being said, AMD probably has other reasons to use an Al layer at 65 nm because this scaling effect will likely only really start to bite at perhaps 32 nm and below.
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