By default yes — 48 kHz WebM audio becomes 48 kHz M4A audio, 44.1 kHz becomes 44.1 kHz. If you need to downsample for compatibility (e.g. 96 kHz studio masters to 44.1 kHz CD-quality M4A) the sample-rate dropdown does this with high-quality resampling.
Audio demux + transcode runs much faster than video re-encoding — typically 5-15% of source duration. A 1-hour WebM -> M4A finishes in 3-9 minutes on the standard pipeline. If the M4A codec matches the source codec already in the WebM (common for AAC inside MKV / MP4), it is a pure remux and runs in seconds.
M4A formatek pelê deng e ku ji nêz ve bi MP4-ê ve girêdayî ye. Ew bi piştgirîkirina metadata re berhevkirina deng-kalîteya bilind pêşkêşî dike, ku wê ji bo serîlêdanên cihêreng maqûl dike.