It has been made more difficult now aswell even for a fam flight for ATC. I asked on a thread recently and found out the answer is no unless you book in advance with head office and even then I believe you have to provide a LOT of security info.
I asked cabin crew a couple of months ago and had my ID, licence the works to show but unfortunately your hands were tied.
On my next flight back home I hope to prearrange a cockpit visit again. We used to get it quite often.