'Digital' is a technically not accurate description of amplifiers that use class D power amps (small and lightweight) and/or switch mode power supplies (SMPS... REALLY small and light weight). I think the 'digital' description came from the 'D' in class D, but the class D amps are still analog. I guess from the EE's who post on the site, there is a 'digital' type 'on/off' thing going on with the SMPS, but again, not a very good or useful descriptor. Just think of 'digital' as representing 'small, light and efficient (i.e., they don't waste a lot of power generating heat like older designed amps).
These days, it is a zero issue. Any amp that is really small and light like the Markbass, GK micro's etc., uses the switch mode power supply design... eliminating big, heavy power transformers. Watt for watt, they sound identical to the heavy iron these days.
The type of power amp is also a moot point, since most of an amp's voicing and character comes from the pre. EBS uses class H power amps, the popular Markbass LMII/III uses a classic class A/B power amp, and most of the other micro's use class D. There is no way to pick 'the type of power amp used' in a blind test anymore.
Interestingly, one of the 'warmest, most vintage sounding' micro amps out there right now is also the one that has the most 'modern' components. The TC RH450 has a class D power amp, and SMPS, AND a true 'digital' preamp!
So, regarding what is inside the box, ignore it and use your ears.... all these small, lightweight executions have their own tone profile, from the bright, modern voicing of the Genz Shuttles, to the super wide, aggressive voicing of the GK heads, to the warm and clean and relaxed voicing of the Markbass heads, etc., etc., etc.