Following the PlayStation Network downtime over the weekend, Sony has apologised for the disruption and confirmed that PlayStation Plus Subscribers will be compensated. A post from @AskPlayStation on X confirms that PlayStation Plus will receive extra days of service.
The post on X reads:

After checking our PlayStation Plus subscription, the renewal date of the subscription has not been extended yet.
Sony offered identical compensation in 2015 following similar PlayStation Network disruptions during the Christmas holiday period.