I emailed VOSA to get a definitive response over the rumours, and also statement on their website, about checking for chips, remaps and DPF deletes. Resonse below:
"There will be quite a few changes to the MOT test next year but checking the mapping or "chipping" of ECUs is not included. A visual check to see if the emission control equipment has been modified is included in Directive 2010/48/EU but has not been considered a valid inspection as most are hidden under covers or behind trim etc and it is not always obvious that they have been modified (e.g electronically)..
I do not know of any future intention to include it but that is not to say that it will not happen at some time in the future.
I hope this information has assisted you with your enquiry, but if you have any further questions please do not hesitate to contact us again. "