Or perhaps they've seen the relative age of fans while on tour and decided that introducing their music to a newer generation could allow them to keep performing and making a living.
Well, looks like they've got a few options given what others in their "Old School Early '90's triphop" cohort have done: 1) hope for a Black Eyed Peas - like resurgence; 2) get a reality show (worked for RDMC); and 3) 40-something OG's and B-Girls are likely to have more disposable income than their 18-year old off spring, doing the tours might just be a comfortable enough plan...
God. Please. Don't compare Black Eyed Peas and De la Soul. 3 feet high and rising is a masterpiece of the 20th century. If this helps newer generations acknowledge their work, it will be incredible.