Likewise, using such words used to convey how this appears to humans on Earth does not mean someone believes anything other than axis rotation of spherical bodies, the world moving in outer space to orbit the sun, is true or probable. They would not have to believe that Earth is a landmass on a disc, Ra riding far above in the sky to illuminate the world every day, as is said about the ancient Egyptians. They would likewise not have to believe any other erroneous or improbable things about cosmological metaphysics. However, even in contemporary America, people use non-literal language all the time to speak of the sun and world we live on. In all likelihood, these individuals will not be accused of automatically believing in a flat Earth. I have written before about how a spherical Earth is very evidentially probable and is something certain Biblical verses are very congruent with, even if they are not direct acknowledgement of a spherical planet [1].
There are also verses like Revelation 7:1 and 20:7-8 that refer to the "four corners of the earth." While parts of Revelation are absolutely presented as literal, with some figurative elements receiving their literal explanation (Revelation 1:19-20 with verse 12), this is the book of the Bible most prominently featuring exotic imagery and poetic descriptions. It does not follow from the mere phrase "four corners of the earth" that these words are to be taken literally in the strictest sense. One could use such language and still be thinking of the world as a sphere instead of a square or rectangular (squares might be formally defined as a subset of rectangles, but this is not how many people colloquially use the terms, and words only mean whatever is intended by them, as is directly relevant to the Biblical phrase in question). The Bible does not say "The earth is not spherical," something that would directly put forth the notion of a flat planet.
What it says could easily be a poetic summary of the four cardinal directions or the full scope of the world. If this by necessity means the Biblical authors think the world is flat or a disc, then modern speech referring to a rising or setting sun would by necessity mean all of us who use such words think Earth remains in place and it is the sun that goes around the planet. Of course, the latter does not necessitate that belief, and neither does the former require that someone believes in a flat world. Even separate from the Biblical verses that likely endorse a spherical world (like Luke 17:34-35 seemingly saying the return of Christ happens both at night and during the day), there is nothing about the "four corners of the earth" that in any way claims the planet is flat. Besides, many of the people who might object to this phrase in Revelation 7:1 and 20:8's might also think Revelation as a whole is figurative to the point of great ambiguity, which would contradict their assumption that the four corners wording must be or is probably literal.