At the risk of going back on thread for which I apologise.
It looks like all potential bidders have passed the PQQ stage, what this means in reality is that DfT didn't manage to assess them properly and as such are hoping for a bit of natural down-selection.
The way to do this is to completely change the time available to react by reducing it, with no notice, from 12 weeks to 4 weeks. This will effectively give those new players no time whatsoever to firm up tentative plans that may have been on hold pending PQQ success. 12 weeks was challenging enough, 4 weeks just plays into the hands of previous SAR bidders.
A sceptic might suggest that this automatically reduces the field to 3, FBH, CHC and maybe Bond if they can secure the right partners, and this may be the aim of the "authority". I'm a sceptic.