I don't doubt that. Everything changes. But whether you'd be able to hear any difference in a properly functioning design (with quality components) is another question. I'd say no.
Q tends to increase with use in all electronic parts that I can think of, but there could be exceptions. It's entropy doing its thing, everything works its way down the potential energy slope. For capacitors it's quite obvious. At Essence Electro Acoustics, we worked for many years with Bas Lim, the design chief at Rel-Cap and Sprague. He did some special runs for us. We used very-low-ESR electrolytics, monolythic ceramics, silver mica, polystyrene/tin, and many others. When Q goes up the sound gets better...until something fails. Some parameters *do* worsen at the beginning, like leakage noise from electrolytics. If you bother to build and test gear for many years you will learn this.
Comparing a five-year-old amp to one with 24 hours on it was always unfair, the old amp rested on a long-lasting plateau of musicality. You had to mentally filter out the closed, nasal aspect of the new amp to make a fair comparison. Our newer gear was clearly better, but the burn-in period is as inevitable as death and taxes.