My (source: am Fr*nch) reasoning is this: the reason why Macron lost many seats to the left in 2022 was because they rallied around a clear leader, Mélenchon, whose programme clearly answered some "radical" demands, and who had won so much votes in the last election compared to other candidates on the left that no one could credibly oppose his NUPES election agreement. The reason Macron is dissolving the National Assembly now is because it is the Socialist Party (PS) that won more seats than LFI (Mélenchon's party) in the EU elections, while lacking the clear leadership Mélenchon had and likely not being willing to concede to the more "radical parties" like Mélenchon could towards the more traditional socdem parties like the PS in 2022. In other words, Macron knows the left is divided, and that its presumed leader, for the time being, is a neoliberal type from the party that gave us François Hollande, that is: someone he could work with. On the other hand, the far right winning big is not as big as a concern for Macron as prevening LFI from staying the major playor on the left in the next elections, since he knows he can work with the far right (hell, he kinda already does, just not officially) but not with LFI. So, in short, my belief is that for him it is worth the gamble of maybe having to concede another victory to the far right (also, since the legislative elections are in two rounds, he's probably still banking on the "beavers" voting as a barrier the far right on round two like they've done until now) in order to contain the left.
My (source: am Fr*nch) reasoning is this: the reason why Macron lost many seats to the left in 2022 was because they rallied around a clear leader, Mélenchon, whose programme clearly answered some "radical" demands, and who had won so much votes in the last election compared to other candidates on the left that no one could credibly oppose his NUPES election agreement. The reason Macron is dissolving the National Assembly now is because it is the Socialist Party (PS) that won more seats than LFI (Mélenchon's party) in the EU elections, while lacking the clear leadership Mélenchon had and likely not being willing to concede to the more "radical parties" like Mélenchon could towards the more traditional socdem parties like the PS in 2022. In other words, Macron knows the left is divided, and that its presumed leader, for the time being, is a neoliberal type from the party that gave us François Hollande, that is: someone he could work with. On the other hand, the far right winning big is not as big as a concern for Macron as prevening LFI from staying the major playor on the left in the next elections, since he knows he can work with the far right (hell, he kinda already does, just not officially) but not with LFI. So, in short, my belief is that for him it is worth the gamble of maybe having to concede another victory to the far right (also, since the legislative elections are in two rounds, he's probably still banking on the "beavers" voting as a barrier the far right on round two like they've done until now) in order to contain the left.
Unfortunately this makes a lot of sense and is probably the correct explanation.