If I leave through my employer’s voluntary departure-job preservation plan (“PDV-PSE”), will I be entitled to a pension with no rate reduction once my period of paid unemployment has ended?

Yes, provided that you meet the age and length-of-career requirements on the date your unemployment benefit entitlement comes to an end (age 50/ 20 years of employment). Indeed, a departure as part of a voluntary departure – job preservation plan is treated as a layoff pursuant to article R6527-27 of the French transport code.