It definitely isn't rotated, position is rounded and even if it wouldn't be it is using linear sampling which should result in blurry font not pseudo italic with missing pixels. In anyway if results by newest monogam pipeline for fonts (even when correct) are close to XNA I would still greatly prefer superior Nuclex results, I mean.. it's different league of quality.
Now I need to figure out how to use nuclex with XNA just for font compiling while using Monogame with VS 2015 on Win 10 for everything else without making any mess.
Really tho, if monogame would start using same opensource rendering engine for fonts as Nuclex they would have my eternal gratitude. I understand if monogame is trying to get visually as close to original XNA as possible.