There's actually an agreement between the FFTT and the CTTA, that's why there are actually many top 100/200 WR chinese players involved in the Pro A, like Xiang Peng, Xu Yingbin, Sun Wen and so on.
This has led to a major controversy this season: as the CSL has been scheduled in mid season, December for instance because of the Paris Olympics, the CTTA stated that the chinese athletes could play the phase 1 in France, but not the phase 2. The french leagues are organized in 2 phases: from September to December, then from January to June.
The FFTT stated also that NO athletes could be involved in 2 different leagues at the same time, means here foreign leagues, if those leagues are organised by ITTF affiliated associations. That's why at Jura Morez's french Pro A club Aruna can play the MLTT (not organized by the USATT) and the french Pro A at the same time, but Sun Wen could not play the Pro A after being hired to play the CSL, organised by the CTTA. Jura Morez decided to put Sun Wen on the team after January and has been sanctioned, leading to an awful drama when Jura Morez's President decided to withdraw from the Pro A: he could not bear to pay Sun Wen for only one phase and not being able to put him on the team for the playoffs next June. At that time Jura Morez was the leader of the Pro A
Now guess what ? this agreement will let the Lebrun Bros. being hired for the next CSL in.... July (no Pro A championship), and the FFTT has decided to remove that "2 leagues" rule that led to too much drama. Means there will be much more foreign players in the Pro A, much more french players making money elsewhere, and more chinese players allowed to play both phases of the french Pro A because of the CTTA/FFTT agreement.