I agree it’s likely it probably has been used unthinkingly, but that’s what it says! Perhaps someone from NRE can clear that up. And why isn’t it in the NRCoT?
It doesn't really matter that it's not in the NRCoT. It's a statement published on behalf of the trader (as NRE is published on behalf of all TOCs) and therefore one is entitled to be influenced by, or rely on, the statement - it then becomes a term of the contract. This comes from
Section 50(1) of the Consumer Rights Act 2015.
But even if we ignore that for a moment, it would be laughable for SWR to suggest that the disclaimer in their Passenger's Charter means they can simply change the timetable and no longer be liable to pay compensation. It would effectively give them the right to unilaterally vary the contract (and, in effect, give them the right to unilaterally judge when they are or aren't in breach of contract), and that is not a right afforded to them in the NRCoT.
Such an alleged effect would also place the clause at serious risk of being declared an unfair and hence unenforceable term given the context of a consumer contract. This is because a clause intended to have such an effect would likely come within the ambit of paragraphs 2, 11, 12, 13 and 16 of Part 1 of
Schedule 2 of the Consumer Rights Act 2015.
And even if we ignore
both of the above points, the NRCoT still guarantee compensation for delays of 60 minutes or more, with the only exemption being when the delay is "entirely outside the control of the rail industry". As I have previously explained, a strike is plainly not such a circumstance and thus no exemption applies. So it simply isn't within the remit of SWR to exclude compensation for certain circumstances.
They couldn't credibly claim, either, that they only offer 'Delay Repay' compensation for delays based on the timetable in force on the day of travel, and if you are claiming against the timetable in force when you bought your ticket, that they instead offer 'NRCoT minimum' compensation (which has a higher delay threshold and compensation amount). No such position is made out in their charter and accordingly their attempts to exclude liability when they change the timetable is for naught.
It is therefore clear that there would be at least three different reasons why any attempt to evade liability through that clause in their Passenger's Charter is entirely ineffectual. Of course, that will not stop SWR from incorrectly rejecting claims made on the basis of the timetable in force at the time of booking. Unfortunately there is no effective means of recourse for such widespread wilful evasion of debts and breach of contract and consumer law, as group litigation is notoriously difficult and limited in this jurisdiction.