just found this:

Although episodes are predominantly recorded weeks before they are broadcast, occasionally, EastEnders includes current events in their episodes. In 1987, EastEnders covered the general election. Using a plan devised by co-creators Smith and Holland, five minutes of material was cut from four of the pre-recorded episodes preceding the election. These were replaced by specially recorded election material, including representatives from each major party, and a scene recorded on the day after the election reflecting the result, which was broadcast the following Tuesday.[47] The result of the 2010 general election was referenced in the 7 May 2010 episode.[48] During the 2006 FIFA World Cup, actors filmed short scenes following the tournament's events that were edited into the programme in the following episode.[49] Last-minute scenes have also been recorded to reference the fiftieth anniversary of the end of the Second World War in 1995, the two-minute silence on Remembrance Day 2005 (2005 also being the year for the sixtieth anniversary of the end of the Second World War and the 200th anniversary of the Battle of Trafalgar), Barack Obama's election victory in 2008,[50] the death of Michael Jackson in 2009,[51] the 2010 Comprehensive Spending Review,[52] Andy Murray winning the Men's Singles at the 2013 Wimbledon Championships,[53] the wedding of Prince William and Kate Middleton, the birth of Prince George of Cambridge.,[54] Scotland voting no against independence in 2014, and the 100th anniversary of the beginning of the Great War.

No more than the answer on the xmas crackers being Last Christmas. Or the song being played on numerous things over the holidays, including Emmerdake and Corrie on Xmas Day and EE on Boxing Day.

I do think it was a bit more unintentionally spooky than simply hearing Last Christmas being played (at Christmas, shocker!). It was more the unexpected sound of George Michael long-dead fictional superfan's voice than the fact she played Last Christmas on Dot's mixtape. Just like the sad irony of a man who famously recorded Last Christmas passing away on Christmas Day.

When England were knocked out they mentioned it and something else in same scene, may have been small debate on brexit

I guess you must listen to Alanis Morissette. It's coincidental, not an irony.

Why on Earth were some of those last minute inclusions? I mean you know in advance when an anniversary of something would be. Unless they filmed those scenes but edited them in once they were sure which episode would air that day in case of schedule changes.

I watched the episode a few days late and found it emotional to watch.

I remember when Princess Diana died Brookside had a specially recorded scene inserted but I don't remember EastEnders doing anything.

Club Tropicana was playing at Ronnie and Roxy's last night.

I would have expected them to cancel (move) at least the Monday episode ? ok don't know how many episodes a week it had then of course and what days they were shown.

I have always maintained that the only irony in that song is its totally lack of irony

Never thought of it like that before - so true!