"The Boundary Commission sent over its final recommendations for the new parliamentary boundaries in September 2018.

The Commission said it was “confident” its new map would be the best outcome for the future of parliament.

In 2011, MPs in parliament backed the principle of undertaking a reduction in the number of MPs.

The law requires the size and shape of parliamentary boundaries are periodically reviewed to keep updated with demographic changes which influence a number of eligible electors in each area.

The last review took place in the mid-noughties, which ensured changes were enacted for the 2010 general election."(wales 2006, Englanf 2008, N Ireland 2007, scotland 2005)

The proposed changes are twofold?:
1)Shrink the number of snouts in the trough.
2)To ensure the numbers of the electorate in each constituency are equal.
https://www.express.co.uk/news/politics/1198254/election-2019-boundary-changes-effect-2019-general-election
It has to be pointed out the author of the article is a total idiot for asking how the changes would impact the december election. How a future event can possibly impact a past event totally escapes me. These changes have not been before parliament and hence have not been enacted. THe election was fought on 2010 constituency boundaries.