question as in the header
which is "services cancelled is there a published list?" ...
No single list, I don't think - it depends on when they were cancelled.
* Some services are cancelled permanently or until an alternative is provided - such as the through trains from Trowbridge to places like London (Waterloo) and Brighton, the "super fasts" from Bristol to London, the Bristol to Manchester service, etc
* Some services are cancelled weeks ahead because of engineering works, or because the trains that would normally be used are diverted onto services for Glastonbury or the Cheltenham Gold Cup.
* Some services are cancelled a few days ahead for reasons such as industrial action or predicted extreme weather
* Some services are cancelled overnight when it turns out that the rail industry doesn't have enough people to actually run them, or not enough trains in working condition, or there's predicted flooding of the line on the Looe branch or something.
* And some services are cancelled "on the fly" - points or level crossing failure, train broken down, staff member taken in, person hit by train, etc
Sorry - no single list.