So Commissioner Goodell has come out and made it obvious to all - he wants an NFL team in London and one in Los Angeles. So it would appear he cannot be argued out of the idea. That there are reasons not to do it have been clear to anyone - the fact is neither city has any serious audience for a team, and Los Angeles is the worst sports town in the US. For London the logistics of basing a team there already proved the undoing of NFL Europe, and there is no evidence players want to stay there.
Yet Goodell seems hell-bent on getting teams in London and Los Angeles - even with the idea of eight games a year with rotating teams played there along the lines of the current Thursday/Sunday Night/Monday Night packages. So if the idea is inevitable, it would seem the addition of two teams to the league is also inevitable.
The idea that a team would move from its present city to London or LA has never been a credible idea - the reality is cities all understand the economic benefit of having a team and the possibility of supporting relocation is a dead one - no city will give up its franchise anymore. Jacksonville is often cited as a candidate to move its franchise elsewhere, but this is media types (and some fans) projecting a personal hatred of the city into the argument (it's well know the media hated going to Jacksonville for the Superbowl there - and really never had any credible reason for such hatred).
This is one of two idiotic analytical mistakes made in examining the issue. The other is the tired gripe about "watering down the product" because of expansion, a concept that has never made any sense because it's never credibly defined, plus is commits the ultimate mistake made in economics - assuming a nonexistent limit on talent pool. In economics wealth is created, it is never distributed - this is the fundamental fallacy used to justify redistributionary policies, and of course they've always failed. In sports team talent is likewise created instead of distributed. Claims the product is better with fewer teams is pseudo-nostalgic nonsense - the AFL-NFL rivalry discredited the notion of less is more forever in football.
If this does happen, I'm guessing the London team (the Monarchs, after the NFL Europe team) would be in the NFC East, the division with the highest number of big markets, while LA's team would be in the AFC West, the only sensible place for an LA team. One can feel confident high-profile teams like the New England Patriots will be scheduled against both teams for primetime games to give their debut a dash of glitter.
I'm not sure it's a good idea simply because neither city has shown any reason to feel they even deserve a team. But Goodell seems to have made it inevitable.