I've no idea but the usually reliable MySupermarket.co.uk is showing them as in stock at Sainsbury's (£1.40), Asda (£1.30), Morrison's (£1.29) and Waitrose (£1.40). [All prices are for 200g].
There are a few products that Tesco no longer stocks which is quite disappointing, I can only assume that they have cut the variety of products they sell as they said they would following a customer exodus to competitors.
Are you sure it's not just your store. For example, I use Tesco own brand sweetener tablets; my usual store never has the refill packs, only new dispensers. Whenever we got to a different Tesco we stock up.
Thanks to those who replied.
The question relates to Tesco not alternative suppliers. Tesco haven't ceased to stock them, they just haven't got any to sell.
Judging by today's news, maybe they haven't paid for the last lot?
They're probably committed to using a certain supplier who might, for example, have suffered a major fire at their packaging plant. If Tesco can't find an alternative supplier (with sufficient stocks of cherries and processing capacity to meet Tesco's requirements, at the price that Tesco is prepared to pay), then there's little that Tesco can do about it.