The new Huawei P30 and P30 Pro just came out and they are already breaking new records in China. According to Tmall's data, the new generation Huawei P-series has received ten times more reservations than the P20 family.
Last year's record holder was the P20 duo, but it has now been overtaken by the P30 by a huge margin. In fact, one version of the P30 Pro saw an entire batch reserved in just 5 minutes. And keep in mind that the company hasn't yet announced pricing for the phones in China, so people are pretty much blindly reserving them.
However, these are stats released by just one retailer in China so the average numbers are probably less but it's a clear indication that the new P30 and P30 Pro will outsell their predecessors.
Source (in Chinese)
I did yesterday and you can read my first impressions in P30 Pro readers opinions.