Having had a look at the Sectional Appendix, the down platform at Barnsley is163 metres long and the up 102 metres....so plenty of room for a four car train. The thought occurred to me later that the length restrictions may be because of the short platform at the fairly new station at Berry Brow....and indeed the bay platform at Huddersfield - but, by then, I didn't have time to scroll back through the SA. I find it hard to believe that Northern's planners were completely unaware of a local derby match being played, but it may just have been a case of no spare units being available.
The bay platform at Huddersfield is quite restrictive but it was lengthened (end of 2019) to accommodate 2 car cl150 plus cl153 - I think as part of the same project any other short platforms on that route were also extended to accommodate that formation - maybe as suggested no spare cl153, or even one planned but then not available on the day.
A further lengthening at Huddersfield is (or certainly was) planned as part of the Trans Pennine Route Upgrade to take 4 cars.
In another part of Northern land, yesterday I saw the 15.21 Liverpool to Manchester Airport pass through Deansgate absolutely rammed, 2 car class 195, (not helped by cancellation of the stopper immediately ahead of it although numbers for the stopper at LSP, Warrington West and Central and Birchwood would I'd guess be pretty few with the much faster train arriving in Manchester just minutes behind). The back working is 16.47 ex Airport, 17.08 from Picc and 17.11 from Oxford Road, prime evening peak train (OK less commuters but probably still a very popular train). When TPE had that path from Picc it was a very busy 6 car cl 185 admittedly with including passengers from the other side of the Pennines (and Staly).
In contrast I caught the 16.24 Buxton from Picc (well actually from Stockport as I saw it leave Picc but was able to overtake it on the 16.27 XC) and it was a not at all busy 4 car class 150 - probably around 20 max in any one coach.