Surely a lot of this relies on members of the public giving their mobile number to the TOC, many people will not wish to do this, if you have bought a ticket on line, they will indeed have your email, and could send info this way, OK if you catch it before you leave home, either that or read it when you get back.
As for being on train and having info directed to your mobile, fine if you have bluetooth on maybe, not everyone has, or even wants heaps of apps on a mobile phone.
Sort out the information we have on stations and on trains first, then maybe filter it down to mobiles.
Surprising how many think that having everything done via apps/email/online is the be all and end all, but then will moan when booking offices shut, and guards disappear as surplus to requirements.