Well the thing is that you had a certain form of anticolonial thought that also existed on the right wing of the political spectrum. Not sure they'd make the majority but it's not impossible you'd have certain political currents in National France that just want to get rid of the colonial empire once it has served its purpose.
Also, reformists don't exists solely on the left side of the spectrum: Conservatives can make reforms, they just usually don't have the same aims and goals as Socialists or Liberals. Or when they do, they usually don't use the same methods and/or have different motivations.
Finally, you could argue that there are reformists that have joined National France because the Commune is simply too radical for them. Not saying these people would necessarilly be in power nor marginalized, but they still could be around and possibly gain influence if the right decisions are made (read: done by the player).
I'm not saying otherwise. By all means National France should have a high risk of native anticolonial revolt on its hand (especially since the Commune would likely work towards supporting such dissension) at the start, with focuses only meant to ensure the colonies stay quiet at least until the birthright is fully reclaimed. And even after that happens, there would likely be a colonial question once Paris is recovered: after all, all those Indigenous soldiers that fought to liberate the mainland will likely want some form of retribution for their contribution (in the case National France managed to keep them from revolting by peaceful means) or would still want to get rid of their colonial chains (in the case where National France has basically survived by cracking down on every potential revolt).
Depends exactly on what makes Pétain's entourage. As I said, De Gaulle originally was a protégé of Pétain and depending on the circumstances he could still occupy a high position in the current government. Depending on how the power shifts in Pétain's government and assuming De Gaulle follows more or less his OTL path (split from Pétain's crowd and follow a slightly less authoritarian way of thinking), there could still be reforms around, even if reclaiming the mainland would likely still be the number one priority.
And that's not without mentionning who exactly makes the government of National France. Likely a majoirty of military staff and right-wing politicians sure, but they're not necessarilly meant to be only reactionnaries. The dynamic probably shifts in the Reactionnaries' favor at the start but it doesn't have to stay that way nor to go further right. All depends on how the government evolves.
Could be a thing if the Regime does follow the more authoritarian paths. But I think the player should be left with the possibility of having to avoid doing that, even it's not the most likely choice the AI would make.
