The handguard thing is not new, Hanael put it on their German submission and later on HK put in on their 416A8.
The suppressor is the interesting part, hence the adjustable gas block. But if I go with this why not HK416A5/A7? Unless it is cheaper than HK for points in the bid. Historically HK doesn't seem to get any favor in that UK community since the MP5 days.
Their main competitor in the UK will be some form of colt canada MRR, the question mark is whether the adjustable gas block is necessary - that is a question associated with the suppressor paired up with the rifle, which we do not know.
But I am not sure this glock thing can be cheaper than MRR. I don't think they will get it.
Not sure SIG MCX is submitted, but I have my doubt MCX can perform as well as MRR and 416 in cold weather.