MPs? We don’t have those, it is a Congress like the USA not a Parliament and they’re called deputies.
Either way, this is part of campaign older than the Bolsonaro presidency where mildly left minority elected officials have been threatened, derided, impeached on nonsense charges, murdered, murdered again, or forced to flee the country. Since the last election in which the world has only focused on Bolsonaro losing the presidency the Congress actually got filled to the brim with deputies and senators aligned with his ideology. They are just continuing their age old purge of leftists and “deviants” that started during the USA-backed '64 dictatorship with the means that they have now. There is even some reason to believe [1][2][3] that the USA has ramped up their meddling ever since 2014, possibly due to Brazil’s quick rise in the global power landscape and building alliances with other USA rival countries such as China, Cuba, Venezuela, Iran and others to oppose USA global hegemony and embrace multipolarity. Now that Brazil is building even stronger ties with both the EU, other third world countries and China, the right-wingers are on the back foot and have to lash out. Don’t be surprised if we get another murdered politician soon, with all suspects mysteriously disappearing to Miami.