Other than the major ERP/CRMs there was very little COTS that was as extensible and programmable as these low-code solutions. I think low-code term may have some mileage as its easier to say than "extensible like an ERP, but without the ERP".
And from a business value they're very different: COTS you do not want to modify/adapt to your busines, otherwise you get problems upgrading, etc. Low-code is often used to innovate and differentiate, as a programming layer to quickly change COTS to your business needs.
Disclaimer: working for a low-code vendor.
This is redefining a term after the fact to suit marketing needs of the new term - with the except of bespoke solutions, it has always been possible to adapt COTS products - have you not seen SAP? Dynamics? Even Excel is COTS
I would consider Excel a no-code/low-code (pretty complex macros in there + vba) platform.