Update, November 21: When the OnePlus 5 started disappearing from OnePlus online store in various locations, we speculated that it might have had its day. It now appears that this is the case, based on a quote from OnePlus India's General Manager Vikas Aggarwal during an interview with The India Express:

“If you look at our previous phone, the OnePlus 3T, the last batch was sold out during Diwali and now the product will be discontinued. The same goes for the OnePlus 5, which will also be sold out in sometime, and we’ll have only one product, [the] OnePlus 5T, in the market."

This, says Aggarwal, is simply part of OnePlus' strategy to maintain a product line featuring only its latest smartphone. Thus, once the OnePlus 6 arrives, you can expect the OnePlus 5T to be discontinued shortly thereafter also. Note that though these comments related to the Indian market, where the OnePlus 5 can still be purchased on the online store, the strategy is unlikely to differ in other regions; the device has been unavailable for the past month in the US, UK and elsewhere, showing no signs of return.

This is a strategy that can frustrate some fans, who might prefer to get a lesser model at a lower price than only have the option of the latest, most expensive edition, but it makes sense given the size of OnePlus. Let's not forget that it was only with the OnePlus 3 that the company was able to let go of its invite-only purchase system which had helped it keep overheads down as it established itself in the market. If you're not a technology giant like Samsung, Apple, Huawei etc, supporting multiple devices at once can be a significant challenge.