My point is this:
Someone who works for Tesco has told me that senior staff have been told the reason is a supply issue.
Someone who has posted on Twitter has been in email communication with Tesco and been told it is not due to lack of customer demand but to a new supplier and change of packaging.
It is not unfeasible that the admins managing the Twitter account can see that the product is listing as "discontinued" and have decided themselves that this would be due to a lack of demand and that is what they have been telling enquirers on the Twitter account, including me, yesterday.
I am not saying that the Twitter admins are lying - but have possibly incorrectly assumed that this is a discontinued product; whereas, the supply chain from the Ukraine or another country may be the issue, an alternative supplier has been sourced and the product may be back on the shelves in a few weeks' time.