No. Its literally because the Train Planning team does not have enough resources to created a reduced plan meaning their only option was to use the reduced plan for the London Victoria Blockade at Christmas with trains diverting into London Bridge and roll that over.
Why on earth don't they have adequate planning resources to replan a more appropriate timetable after almost three weeks when there was a perfectly good although heavily reduced (especially on the normally extensively served Victoria to Gatwick and Brighton line) service timetable that ran for 7 or so months in 2020 that they surely could have got up and running again within a few days in the week starting Tuesday 4th Jan and that timetable did not divert initially all and then subsequently still the vast majority of services in to London Bridge and also ran a shuttle service from Dorking to Horsham at off peak times including Saturday evening. The only logical reason to divert to London Bridge originally over Christmas Week was because of engineering works on the lines in to London Victoria but that reason disappeared on Tuesday January 4th yet still the diversions to London Bridge and still the ridiculous last train out to Horsham via Dorking at 1725 every day continues. Also absurdly I notice that on that slightly amended (just one additional early morning service) Saturday timetable the first train from London Bridge to Ockley is at 0725 but the first regular hourly train from Ockley to London Victoria is at 0824 after the isolated 0600 service converted from a normally out of service train from Horsham to Victoria on a Saturday. So clearly they think this timetable is only designed for walkers going out to Surrey for the day and not for people going in to London on a weekday to use hospitals, undertake urgent business tasks and the like.
Had my LinkedIn profile viewed a few days ago by a person who describes themselves as being an "Amended Timetable and Rolling Stock Planner at GTR (Govia Thameslink Railway)" on their LinkedIn profile but of course no contact at all by that person by phone or email to discuss my issues with the train planning team. Only phone interactions I have had have been with Teleperformance customer service call centre in Bristol, who effectively don't have any proper knowledge or understanding of the Southern network and its amended service patterns of any kind (they don't even know or seem to care where any of the stations are located geographically) and a call back from a lady who is some kind of Customer Liaison Person with GT Railway, who could offer me no specific explanation or justification for why Southern is doing what it is doing running a Saturday service with no evening service south of Dorking for weeks on end while not even offering to pay for a replacement taxi south of Dorking at times of day when trains would normally run on a weekday.
The mask mandate and work from home edicts are all going by this time next week and recorded Omicron infections and therefore Southern/GT Railway staff absences will also be falling fast. Yet despite that normal service still not listed as returning on the current Southern journey planner until Monday 21st Feb some four and a half weeks from.
Seems GT Railway and the Department For Transport are in a conspiracy to recoup past financial losses during COVID from rail users using the excuse of Omicron. Any claims they didn't initially have enough staff working to plan a more appropriate timetable than the Christmas Saturday timetable are surelynow long since busted in terms of any credibility.