I don't think the wording is woolly at all, if anything, it suggests a certainty that they couldn't possibly have any certainty about 'we have taken the decision to recommence flights on 17 June'.
They might be able to, but I really have no idea how realistic that is. It would have been better to say that they hope to recommence from 17 June, which would still have the message that no-one is flying before 17 June, but we might see improvements from that date, but not making any promises as all they can do is review the situation closer to the time.
As it happens we had flights booked with jet2 for the last week in April, so have known for a while that they are not happening, especially as Spain will be in strict lockdown until at least the day we get there.
It's a flight only booking and our accommodation is with friends so we only need a refund on the flights, this has not yet been offered and that's what we'll be asking for, rather than a rebook, if we don't go away in the Spring, we can't really go before mid September and we'd rather just start again later in the year, rather than having to commit to dates so far ahead now (we never book a holiday more than about 2 months in advance)
I'd be very cautious about taking vouchers from airlines or tour operators at the moment, as these could become worthless if they went bust. People might have other avenues for refunds, such as ATOL/ABTA or credit cards, but I'm going to be pushing for the cash as is my right.