I have concerns about changing ESL to Language and Culture, and defining it as Multiculturalism, a term that is itself vague and subjective. These are changes at curriculum level and need to be worked out thoroughly, debated and would have implications for training as ESL teachers are trained to teach language, not Mulitcultural views of Culture.
While language and culture are intertwined and cannot be separated artificially and knowing about other people's cultures is a good thing, what criteria are to be used for inclusion in the syllabus? Will gay rights, female circumcision, death camps in North Korea, and conflict in the Middle East be on the syllabus? Or will it be the usual chirpy ragbag of 'a day in the life of someone in a Nepalese village', a description of Diwali and a biographical sketch of Wole Soyinka?
Before elevating culture to the upper case and granting it equal standing, I would want to know what the intended outcomes are and how these would be measured. The language progress can be measured in many ways, whether by competencies, other output or exams, but how do you assess someone's multiculturalism? While the intentions may be good, I think that the whole idea is based on pre-suppositions which should be more explicit.
How would people respond in your system to a student who handed in a brilliantly written piece of work, showing detailed research that was anti-multiculturalism or racist, etc? Would they be assessed for their writing and ideas or would they do badly for going against the grain?
Is there not also a risk of creating a 'Disneyworld' view of other cultures in an attempt not to cause offence? In a British school recently a decision not to teach the history of the Holocaust was taken in order to avoid causing a perceived potential offence to Muslims. It is against this backdrop, that I find the concept worrying because there needs to be clarity about the aims and purposes of what is taught.
It is good to know about other cultures; I have lived abroad for many years and found it greatly enriching. I have no objection at all to multicultural materials being included and taught, and fully support that. However, the elevation in status concerns me.
You mention 'Culture from different/ all parts of the world'. All of the world is out of the question, so there has to be a selection. How will this selection be made? At the moment in ESL materials, it seems to be fairly random, like giving a few flavours and hints about the cultural diversity of the planet, which is fine by me. But if it is elevated in status, then more important decisions have to be made about inclusion and, probably more importantly, exclusion.