Yoda is 900 years of age; given how much English and other languages have evolved over time, to a point were someone of this day and age would not be able to comprehend what an English speaker was saying only 300 years ago? Could Yoda be speaking correct Galactic Standard, only an older version that was no longer used?
Canon: Most Likely Not
Star Wars Rebels' Bendu talks to Kanan and Ezra in modern Basic - unless you assume some form of Force communication translation (which I wouldn't since it's not telepathic or anything). According to the official website, it's an "ancient" being and can thus safely be assumed to be at the very least as old as Yoda, probably much older, I think.
It's still possible that Bendu updated his language skills while Yoda did not, but... that's probably really stretching it.
Legends: Definitely Not
According to Wookiepedia, referencing "The Written Word" and "Power of the Jedi Sourcebook" on it, modern Galactic Basic Standard was established after the Vultans joined the Republic around 14.000 BBY. The history of Galactic Standard is divided into eras - similar to real world languages - with "modern" Galactic Standard being the latest after Old and Mid-Galactic Standard. A major shift in the language, like turning grammar upside down from Yoda's to "regular" is, would certainly be considered a new distinct era.