You should send an amended Witness Statement, either having received the claimant's WS and documents according to the Additional Directions and responding to them in your revised WS, or - in the absence of these - noting that these documents have not been provided by the claimant. So I wouldn't file your revised WS until the deadline, ensuring that the claimant is also copied.
Since this date (16 July) is, I think, also the deadline for the claimant to pay the court fee, I would not be surprised if the claimant discontinues the case. Obviously if that happens, you don't need to do anything more. The claimant should send you a N279 Notice of Discontinuance.
The documentation requirements on the claimant in the Additional Directions make it more likely that they will give up rather than provide these.
MCOL has no further part in the process once a case has been allocated to a specific court.
MCOL is out of the loop once a case is allocated to a court.
Do not talk to DCB Legal, as you haven't done. There's nothing to your advantage in talking to them - no record - unless you're prepared to pay them money.
I would advise being seen to actively engage with the court and its directions, as you say you've already written the documents and it does no harm to resubmit them with appropriate minor modifications on the deadline date.
