You are correct. Users can still use the Guest account to access LCR. The disadvantage to the Guest account is that additional apps (e.g. Member Tools), preferences, and local file storage are not available options. Everything gets reset when the user is done. That’s not a problem for many users. But it could be a detriment to frequent users. For example, display preferences, including for external displays, for optimal comfort, convenience, and efficiency would need to be set every time the user logs in. Normally not a big issue. But when a clerk and a counselor have family and/or other members to attend to, being as efficient as possible when processing donations every week can mean a world of difference.
For this reason, I’m also at a loss to fully understand why Bishopric/Branch Counselors are not included in the list of users who can create a local profile/account. I would imagine some counselors may also benefit from the added features available only to users with a local profile/account.