According to the "Huawei cyber security evaluation centre" (HCSEC) oversight boards annual report to the national security adviser of the United Kingdom (note: HCSEC was a joint lab between NSCS, GCHQ and Huawei with a lot of access to internal documentation and firmware source code and so on to check if they are telling the truth when they promised there is no backdoor for the chinese ministry of national security in the 5G equipment) their quality and basic security processes are so bad, that it is believable that all the vulnerabilities are unintentional. However they did improve in the years prior to being kicked out, so you are not wrong that it was somewhat of a bandwagon move following the us sanctions.