No—Sly Cooper 4 has never been officially announced. The last main entry, Sly Cooper: Thieves in Time, launched in 2013 on PS3 and PS Vita (developed by Sanzaru Games).
Extremely unlikely. The series is a PlayStation exclusive. A remaster collection could theoretically come to other platforms, but no rumors exist.
For now, replay the trilogy on PS3 (via PS Now/Plus Premium) or PS Vita.