With over 700Billion in assets - this is a pretty big bank. I think this is just a polite tweet - nothing more... so yes, for now I'm pegging this as absurd!
It's not just a big bank. The Commonwealth Bank was actually Australia's central bank before the establishment of the Reserve Bank of Australia in 1960, and was not fully privatised until 1996. They've also been well aware of Bitcoin for quite some time now. This is big news.
This is not big news. This is a company giving a standard line for a feature request that they probably didn't even fully understand. If they did understand it, they wouldn't say they were going to pass it off to their development team because adding Bitcoin would certainly not be just a technical decision. It would have to filter through all kinds of decision makers in the bank.
Nothing to see here folks.