There are no plans that I know of, but I would be surprised if Katakana (and even Hiragana) does not change over time. Writing systems tend to change with time, to better reflect natural changes in the languages they represent. So the real question should probably be whether there will be a change soon.
And maybe there will be change soon, since already some Japanese can perfectly distinguish between [si] and [shi], snd it seems like the Japanese government isn't too conservative about small changes to the gairaigo spelling rules.
Anyway, I'm not sure that there is a definite answer to your question. Unless the Ministry of Education (which is in charge of these things, AFAIK) is working on a solution right now, everything we can say is just speculation.