Hi j17wang,
From what I've read, that is a major thrust of its diversification, the 45nm fab is to take care of that, while waiting for their 28nm FAB from SMEE and to produce chips from it may take a minimum of 2 years. I maybe optimistic, The damage to Huawei smartphone business if you include its stock of chips may well be less than 6 months, if all its plan had been successfully implemented.
My main worry is that Huawei may strain its resources, it had to cover both legacy tech and new tech both at once. They will encounter less problem from financial side with govt providing support, but on the engineering side, recruiting the right talent and motivation will be challenging.