A line that would in effect link the WCML with the MML, ECML and over to the WA line would surely prove popular for many users, as well as during disruption (FCC even now publishes a booklet on changing lines, using buses, when things go wrong). Train usage now is nothing like it probably was when the last rail line was open.
The former route from St Albans to Hatfield and WGC would need a lot of work and a fair bit of compulsory purchasing so I doubt it would happen. Even a tram or similar would still need land to be re-purchased.
And of course there would be less justification when some parts are now fairly well served by bus, with Uno running many routes from St Albans to Hatfield even until very late.
The former route from St Albans to Hatfield and WGC would need a lot of work and a fair bit of compulsory purchasing so I doubt it would happen. Even a tram or similar would still need land to be re-purchased.
And of course there would be less justification when some parts are now fairly well served by bus, with Uno running many routes from St Albans to Hatfield even until very late.