The Emitter amps have an amazing number of electrolytics, between their power supplies and the capacitor banks in their amplifier chassis.
The good news = Germans have a tendency to overbuild their gear.
My guess would be: their engineers chose some of the best caps available, for that creation.
Still: any electrolytics can dry out, start leaking, internally short, or explode, without any particular excuse/warning.
The perfect electrolytic just doesn't exist.
Given your system's initial price and what it would cost to repair it, if something catastrophic were to occur; a comprehensive testing of all those caps, by a competent Tech, would (no doubt) be a great preemptive/preventative measure.
Kind of like: someone interested in their health, getting a physical now and then, by a good Physician.
Electrolytics are one of those things that (especially when they dry out slowly) can have an effect like VERY slowly raising the temperature of the water around a frog, one degree at a time. The critter's perfect at ease, until it croaks (about 40 degrees C).
Likewise: slow changes in the presentation of sound systems and the adjustments our ears and brains can make.
Happy listening!