It was feared as the death of Irish provincial ambitions on the biggest stage.
The premier European rugby's costume change from Heineken Cup to Champions Cup in 2014 saw the-then Pro 12's representation reduced from 11/24 teams the year before to just 7/20 for the new season.
By 2016, French and English clubs who had forced the reformat were using debt and billionaire backing to outspend their Celtic rivals by a factor of 10.
Leinster and Ulster were the last teams from outside the dominant duo to reach a final - when they met in the first all-Irish decider in 2012.
But the outlook isn't all gloom for the Irish provinces.
Leinster and Munster both contested semi-finals last year and they, along with Ulster, are on the brink of a notable achievement.
Leinster's victory over Exeter, Munster's trouncing of Leicester and Ulster beating Harlequins means that Irish provinces could claim a back-to-back treble over English opposition for the first time in the competition's history.
Irish and English teams have met in 15 back-to-back fixtures since the double-header was introduced in the 1999/2000 season.
In that time there have been only six doubles.
In the 2000/01 season, Leinster beat Northampton home and away while Munster gave Bath a double dunking.
Bath must have hated the sight of Irish teams by the time Ulster were victorious against them in 2010/11 and Leinster repeated the trick the following season.
The sole English double came when Leicester beat Munster twice in 2014/15, ensuring they missed out on the quarter-finals for just a second time in 17 years, and the most recent was Leinster's 74-point aggregate destruction of Northampton last year.
Recent history would suggest that despite the comprehensive nature of Munster's 33-10 win over the Tigers last week, they are the riskiest element of of an Irish treble.
Just last season, the Reds thumped the same opposition 38-0 at Thomond before succumbing 18-16 at Welford Road.
It seems the combination of home advantage and wounded pride can be a heady mix as the home side has lost the return leg only three times: Bath to Ulster in 2010/11, Ulster to Northampton in 2012/13 and Leinster to Northampton in 2013/14.
That defeat to the Saints could be a particularly salutary lesson to Leinster as they welcome Premiership leaders Exeter to the Aviva.
Four years ago, Leinster blew Northampton aside 40-7 at Franklin's Gardens, only to suffer a shock 9-18 reversal in Dublin.
Leo Cullen will be wary of a similar turnaround on this occasion.
Ulster fulfilled their part of the bargain last night with a 52-24 hammering of Harlequins at Kingspan stadium. It remains to be seen whether Leinster and Munster can seal the deal.
Listen to exclusive Champions Cup radio commentary of Leicester v Munster on RTÉ Radio One’s Sunday Sport programme (kick-off 5.30pm) and live updates on RTÉ.ie and the News Now app.
Live updates of Leinster v Exeter Chiefs on Saturday (kick-off 3.15pm) on RTÉ.ie and the News Now app.
