Can I use an e-bike jersey for riding a regular (non-electric) bike?

Absolutely. E-bike jerseys work fine on traditional bikes — the relaxed fit is comfortable, the pockets are functional, and the reflective elements are always welcome. The only downside is slightly more aerodynamic drag if you're riding fast, and the more casual styling may not match road cycling culture if you join fast group rides. For solo riding, commuting, or casual group rides on a traditional bike, an e-bike jersey is perfectly appropriate.