The context was in response to the South African teams being added to the European Cup and a confirmation that the current [shitty] format will be retained to facilitate this. The presumption is it may be a once off due to the failure of the rainbow cup (ie. they paid 6 million for 6 domestic derby fixtures only) - but knowing how poorly things can potentially be organised in sport, there is every chance this becomes the new norm.
As of yet we still don't know how the Pro16 will work, they said they're adding 4 new teams and there will be fewer games. I presume we will have 4 conferences of 4 teams. It's the only way we'll end up with fewer teams - play each team in your conference twice, home and away, then one fixture against each other team. Two home and two away fixtures for each conference, rotating annually.
So therefore we end up with: 6 in-conference (3x2) fixtures and 12 inter-conference (12x1) fixtures. 18 fixtures in total, quarter finals (+1 match), semi finals (+1 match) and final (+1 match) so that the maximum number of games for two teams is 21. This is a very minor reduction from 12 in-conference fixtures (6x2) and 7 cross-conference fixtures with 3 potential knockout matches (19 regular season + 3 knockouts for a max 22)
If South African teams were to be permanently added to the European Cup, I'd only be in favour of it if we expand the competition to 24 teams. 8 from the Pro16, 7 from the Top14 and Premiership, one promotion spot for the winner of the Champions Cup and 1 playoff between Top14 and Prem for an 8th spot.
Then break down the group stage in to 8 groups of 3 teams (works out nicely to 1 team per league in each group), so that way we only need 4 weekends to complete the group stage, move in to a Round of 16 (top 2 teams from each group), Quarter Finals, Semi Finals and a Final. The end result is 8 weeks of European Cup action with more high stakes knockout fixtures that include South African teams. (Compare this to the normal format of 6 group stage matches and 3 knockout rounds, we're saving 1 week of European Rugby)
The Pro16 calendar would only see 18 regular fixtures and 4 regular European fixtures, with the potential for 3 domestic knockout fixtures and 4 European knockout fixtures. Minumum games played 22, maximum possible 29. Although you could even add in a Round of 16 in the Pro16, but that feels redundant due to the poor quality of teams in 5th-8th place, even with South African teams, as usually only 1 or 2 non-Irish teams are competitive in any given year