Will any bike lock stop an angle grinder?

Almost none will stop one for long. Even the heaviest hardened U-locks are cut by a cordless angle grinder in well under a minute in destruction tests. A small number of newer locks (Litelok X-series, Hiplok D1000, Altor SAF) advertise meaningful angle-grinder resistance, but for most riders the realistic goal is to deter opportunistic thieves with bolt cutters and hand tools, and to make the lock take long enough that grinders aren't worth the noise.