I am always concerned when those with serious issues like your spouse become motivated for a therapy process that is mostly supportive, or is less than very serious emotional work.
The issues mentioned here are quite serious. Anger, stress, anxiety, alcohol and other drug use...all of this speaks to incredible unresolved pain and hurt. A mindfulness session/course is not going to resolve these huge issues. Why? It is more supportive and focused on relaxation and lighter coping process than what the best practices are for the issues you mention.
The best practices regime for these hard core issues is CBT therapy, at least weekly... as well as support groups that reinforce the therapy and behaviors that are learned in the individual sessions. An on-off contact, or a course is not going to resolve these problems, and this whole approach speaks to a prelude for an excuse...(ex: See honey I went to therapy and nothing changed.)
Real therapy is hard...Why? Everybody wants to get better, but few want to change. In order for your spouse to achieve what is needed, he needs a serious course of counseling, not a mild and gently supportive process.
I agree with you. This does not see to be appropriate. Steven