Even though you may get a better response initially, you will not be able to gain much consistent with your student base.
Dynamics of Yoga
The reason for that is simple. Yoga practice is divided in three levels. Your advanced students will definitely get bored in all levels class. Your intermediate level students will not be stimulated to get to the next step or learn a new pose.
In addition, there are many styles of yoga. Lately we are learning about the chair yoga, which became one of my favorite yoga styles to teach. Vinyasa lovers will easily get restless at Hatha yoga class.
While the experienced teacher can teach various levels, or more than one style of yoga, this cannot be done effectively in all level yoga class. Unless your all levels class is meant to say politely, the beginners class, it will not make much sense. You certainly do not want some students to be intimidated by the skills of the others, or advanced students to be bored with your instructions.
How to Call Your All Levels Yoga
I personally prefer calling my all levels yoga class, family yoga or easy yoga. That way I am creating the right expectations for my class. The goal is not to attract a large number of students only to have a few join the next tine. The goal is to offer a class that will create repeated students with low attrition.