AFAIK twitch usernames do not change often, a cached copied is fine (and probably preferred*) for this scenario. Though really, as long as the URL has some randomness to it a cached copy will not be used.
Each of the following are valid, assuming there aren't more parameters after
http://example.com?1234
http://example.com?=1234
http://example.com?nocache=1234
*: Cuts done on bandwidth and speeds things up because a local, cached, copy will be used if present