When I first saw some of those posts with big fonts I thought that my browser was zoomed in max or that they were using text generators to change the font size, but it was none of them. So I started looking on google to see if facebook has changed something according to the font size, and it resulted that if your post contains less than 35 characters only text without images, and links, then the font size will be automatically adjusted as is in the photo below, otherwise the font size will stay the same as is.
Adjusted Font Size
Normal Font Size
Personally I like the small font size, but on the other side this is a good thing because it makes short post more visible as sometimes the short post can be easily skipped, but now it's totally different as that font can be seen from kilometers away.
What do you think about this change?
Will this update be something useful for you?