The hadith says that Islam will flourish under 12 caliphs.
It doesn't say that only those caliphs can interpret the Quran.
Also, the 12 caliphs after Muhammad are not the "12 imams" of Shiism.
It doesn't flourish. It uses the word "EZA" which means it will remain honorable. The Sunni explanations shows Sunnis and their scholars to be hypocrites per Quran and Surah hyporcites with Prophet (s) calculating his words, has exposed them.
I wrote this in signs of eloquence of Quran:
Salam
Surah Hypocrites is a miracle to me big time. And it's how the nature of Sunnah and Quran compliment each other in exposing hypocrisy.
I will start with the point that hypocrites don't understand that honor belongs to God, Messenger, and believers. It might seem anyone who reads Quran, understands this. It's repeated through out that believers are honorable in God's eyes and disbelievers disgraced.
However, we see Prophet (s) said to Ali (a) "No one will love you except a believer and no one will hate you except a hypocrite" (hadith found in authentic sunni sources).
No one of hypocrites today is going to admit they hate Ali (a). But it comes out, and no one will say "honor doesn't belong to believers", but it comes out.
Prophet (s) said "This affair won't cease to be honorable having Twelve Successors who will exercise authority over the nation"
The meaning of "eza" which Surah Munafiqoon is shown to belong exclusively to God, Messenger and believers. It's get often translated as "glorious" in the Sunni translations of these hadiths.
To deny that Ali (a), Hassan (a), Hussain (a)... to Al-Mahdi (a), are the twelve successors, they say, that believers and Islam was in a state of disgrace in Shiism according to Shiism.
In this way, they are giving honor to Yazid and crooks like him, and denying it from believers like Surah Hypocrites show they don't understand.
The other feature is they measure honor of Islam through richness, materialistic measures, and showing mighty military power and conquering other nations (unjustly or justly, doesn't matter to them).
This another thing of this Surah, it exposes, they are materialistic. Of course, hypocrites say they love God and will pray outwardly, but when tested with this hadith (Twelve Caliphs), they fail the test to see treasurer and true honorable sustenance and richness lies in God's light, power and connecting to him while being aloof from Dunya.
Another it exposes is they are against Tawasul. During Prophet (s) time, they would not come to him to ask forgiveness for them. But these arrogant hypocrites of our time, of course, will come up with an excuse. He is dead and it's shirk to talk to dead they say. This is despite Salah taught by Prophet (s) - Muslims were taught to address the Prophet directly "Peace be upon you O Prophet".
Understand how Prophet (s) calculated the words of Twelve Successors - honor - authority.
Hate of Ali (a) comes out when they deny him as first of these Twelve Successors based on what we see is hypocrisy per this Surah. It also comes out when they go against Tawasul through Ali (a) and seeking Ali (a) as mediator.