What you say...
will there be a possibility that the standards of the English language that we use today might no longer be followed in the future?
...is absolutely true. Imagine that you are posting this question in the year 1400, around the time when the Canterbury Tales was written. Looking at the text, it is clearly very different from any variety of present-day English. Over the course of 615 years of history, the kinds off people speaking English have changed, as well as their culture (including what is perceived to be 'standard' or 'correct' English). Thus, 615 years from now (in the year 2630), we can expect the same kind of evolution to take place.
I should also note that technically this is independent of the World Englishes movement. All languages change over time, as do perceptions of 'standardness' or 'correctness' in all languages. A language does not need to be world-wide multi-ethnic languages like English in order for this to be the case; on a smaller scale, these statements would hold equally true for a language spoken in just a single remote village on some corner of the planet.