No it will be a bog standard 2500m strip - identical to 22L at JFK which I land 747s on regularly. It will suffice for a very large proportion of LHR traffic contrary to Ms Greenings ideas of Perf A......
That's the first time I've seen that suggested, where are you getting your information from ?
AFAIK, as per my previous post, the strip would indeed be 2500m, but the declared distances will be 2200m (similar to the LCY arrangement).