The source If anyone is interested to read more:
http://www.cnbc.com/2017/06/26/barclays-bitcoin-regulators-fca.html
I sadly don't believe that the banking system will ever adopt bitcoin, If they start doing so, It would be for a particular reason they hide (most likely to eventually control bitcoin). The maximum that could happen right now is making bitcoin legal in some countries.
Actualy I think this is very likely. Banks are all about profit and tgp saw the big opportunity to earn with Bitcoins. Maybe they will not go with this in public and publicly they will keep their attitude against Bitcoin but secretly they will test it and implement it for their.own profit, that wouldn't surprise me.