The ramblers wanted the deadline scrapped as it gives more time to register the paths.
The whole process is a bit of a farce really. Paths that are shown on 1864 maps between two farms are being submitted to be changed into public rights of way which are unlikely to get passed. The reason the deadline was scrapped is because of the shear number (tens of thousands if I remember correctly) of paths being submitted that have not been used for generations and that have only come to the notice of organisations like the RA because of the threat of the deadline
I have such a path passing through my woodland. It goes between two farms that probably shared labour or were even related hundreds of years ago. It hasn't been used in over a hundred years according to local knowledge and the two farmers don't even talk to each other. It never has been a public right of way and has no value in being turned into one so I doubt I'll have to fight very hard to get it refused (it hasn't been submitted BTW).
What the ramblers are now campaigning against is the change to the act that will give landowners the right to apply for diversions and the extinguishing of rights of way not used.
In reality, the act is only supposed to cover previous public rights of way that have been lost, abandoned, or forgotten, not 'paths' that were not used by the general public, so I suspect a lot that have been submitted will be refused if there is no evidence of historic public right of way.