More likely that the ST2 design would be terminated before the ST1.
I bought a Stromer closeout last year and very happy with it. Not worried in the least about batteries or motors/controllers etc.
I can't imagine BMC, who owns Stromer, would leave their ST1 owners stranded by abandoning the spare parts inventory... Unless they decided to give up on eBikes altogether. Then they would sell the brand to someone else.