The reason is very heavy, there is no supplier on the market can continue to produce Kirin chip, for Huawei, Kirin 9000 series is likely to be the last flagship chip, but Huawei has a considerable number of product lines, it is not practical to put such a flagship processor down to some mid-end or even entry-level product lines. At least that's how Huawei is preparing for the worst.
Therefore, the Kirin 9000E and Kirin 990E are likely to be transferred to Honor and other Huawei product lines in the future, taking over the position of the previous Kirin 8 series chips.
Huawei simply cannot make the Kirin 9000L, which, like the Kirin 9000, is a contract version of TSMC.
Because the Kirin 9000L is also a 5nm process, and the high probability is TSMC 5nm process.
Kirin 9000L is the eliminated version of Kirin 9000, originally according to the reason this type of chip will not be used, but Huawei has been sanctioned, but any chip that is a little useful must be used up.