Never used them, but from your description sounds either like (a) they are in trouble and trying to profit somehow off funds (by way of interest? I don't know) or (b) they are raising money (from private investors or IPO), and need an accounting change that would allow them to list customer funds as "revenue", which they might be able to under the new scheme in some way, and likely weren't able to in the old scheme.
Bill.com IPOed a while back, in December, 2019. However, they seem to have needed more funding after that, and took on a pile of debt:
> Subsequent to its IPO in December 2019, Bill.com completed three rounds of financing. The company closed an equity follow-on in June 2020, raising net proceeds of $308 million, a convertible debt offering in December 2020, raising net proceeds of $1.1 billion. In September 2021, Bill.com raised $1.9 billion in net proceeds through a concurrent offering of equity and convertible notes.[1]
Looks like a lot of this went towards two big acquisitions in 2021.[2]
