Metallized polyester caps aren't polarized, they aren't constructed like electrolytics. The dielectric's a layer of plastic film, not an oxide, and it works both ways. Note that there's no polarization, even in the spec sheet. Yes, it says "kVdc" on it, but that's just the dc rating.
Unfortunately, the AC voltage rating is always less than the dc voltage rating on poly caps, and usually by quite a bit.
https://www.electro-tech-online.com/custompdfs/2011/11/ABD0000PE111-1.pdf