The Seforno (c.1500) writes this in is commentary to Genesis (8:22):
עוד כל ימי הארץ זרע וקציר וקור וחום וקיץ וחורף ויום ולילה לא ישבותו. "לא ישבותו" מלהתמיד על אותו האופן בלתי טבעי שהגבלתי להם אחר המבול, וזה שילך השמש על גלגל נוטה מקו משוה היום, ובנטיתו תהיה סבת השתנות כל אלה הזמנים, כי קודם המבול היה מהלך השמש תמיד בקו משוה היום, ובזה היה אז תמיד עת האביב... כי אז ישיב מהלך השמש אל קו משוה היום כמאז
They [the seasons] will not cease to function consistently with the system I set after the deluge. The sun will orbit predictably, its orbit will be subject to calculation and its divergence will cause all of the seasons, for before the deluge the sun had remained at a fixed distance relative to the earth all year round, its orbit being circular, resulting in eternal spring ... [In the future] the sun will once more orbit like a circle instead of like an ellipsis.
This translator understands שילך השמש על גלגל נוטה מקו משוה היום as a circular orbit vs. an elliptical one. (The Seforno speaks of the sun's motion, not the earth's but that seems immaterial to the discussion at hand). Before the deluge the orbit was circular and only afterwards did the orbit become elliptical causing seasons.
However, it should be noted that in reality, the elliptical orbit and resultant variable distance to the sun has little to do with the seasons. In fact, Earth is closest to the Sun, around the Northern Hemisphere's winter solstice, while it is farthest away from the Sun, around the north's summer solstice.
However, the seasons are caused by the Earth's tilt. If this is what וזה שילך השמש על גלגל נוטה מקו משוה היום means, then the Seforno would be more correct. Were the earth not tilted, then indeed (IIUC) the Earth's equator would have been coplanar with the celestial equator.