Tl;dr- no, but yes.

Austronesian speaking people from the Malay (island southeast Asian) branch of the language family were the ones who first settled Madagascar.

They are part of the same language family as most Pacific Island languages (except those that have Papuan roots-- though sometimes whether a language is Papuan with Austronesian vocabulary or Austronesian with Papuan vocabulary gets complicated and debated). However, while the people who first settled Madagascar were Austronesian speakers and used similar voyaging techniques as Pacific Islanders; it might be more accurate to call them cousins at least linguistically and perhaps culturally. They are more closer related to Southeast Asian Islanders, who are themselves cousins to Pacific Islanders and whose common migrations are linked in the distant past.

As to whether they first discovered Madagascar. It's hard to say; there is some evidence that Bantu people's had visited. Perhaps to hunt or just have a look around. But sustained settlement of the island seems to begin after the Austronesian arrival and the introduction of new crops they brought with them from SE Asia that were adapted to coastal tropical environments.