It is surprising everyone, including left voters. I don't think Macron considered this outcome seriously when he made his play to dismiss the national parliament. Most likely he was counting on the "Republican blockade" (it's kind of a tradition at this point) to draw all the center to his cause (this would have included, Green, Socialists and the traditional right of Republicans).
Instead, Les Republicains instantly imploded when their leader Eric Ciotti declared we wants to ally with the RN (leading extreme-right party), he got unanimously banned from his party. Another extreme-right party, Reconquête also failed to rally to RN (this is another crazy story, mixing family relations and betrayal). And the left in the most broad sense, is as united as ever, in a unions that seems much more serious and solid than precious failed attempts, giving (my feeling) a lot of hope for voters attached to democracy and justice.
In a nutshell there are 3 possible outcomes we can summarize in Macron's perspective:
Republican blockage: Macron gets again majority in the assembly, he is reaffirmed as the legitimate leader of the country and he can continue the same government and policies. **Macron wins **
Rassemblement National (RN) wins the parliament: Macron is the last standing defense against fascism in France, he will use his powers to veto and block the policies of RN, use this as an opportunity to display RN as incapable of governing, putting him and his party in a favorable position for the next presidential elections in 2027. Macron wins
Le Partie Populaire wins the parliament: Macron cannot govern, he will use his powers to block the policies of the left, these measures are in large part about reversing the unpopular policies he passed in the passed 5 years (often without vote: 49-3), this will discredit him and his party. Macron looses