On September 29, the source wrote (citation):

Reference and base year
This is the first release in which the reference year and last base year have been moved from 2013 to 2015. [...]

Revisions
In line with National Accounts Revisions Policy the entire time series within this release has been subject to revision. [...]

We have revised existing series and updated their unit-descriptor metadata. Properties are otherwise unchanged (see related article).

The data reside in the historical catalog (United Kingdom » National Accounts » Additional Detail » ONS - Detailed - National Accounts » Quarterly | Annual) and include, for example:

• ONSNAABMIQ.IGBR = Gross domestic product, (Mil. Ch. 2015 GBP, SA)
• ONSNAKGA3Q.IGBR = Expenditure - Food and drink, (% Ch. 2015 Q/Q, NSA)
• ONSNAKH5CA.IGBR = Gross trading profits - Private non-financial corporations, (% Y/Y)