[delayed]
could this be a problem for the security of Falcon (aka FN-DSA) post quantum signature scheme?
not really. The hardness of SVP is relevant, but this is a paper giving improved provable bounds for SVP algorithms. heuristically (which people use to choose parameter sizes etc) people assume SVP is much easier to solve, closer to 2^{.29n + o(n)}.
So it's tangentially related, but does not itself imply an improvement on the (heuristically assumed) SOTA for these problems.
Wow, just yesterday I was thinking this exact problem would be a good candidate for AI. Seems it is!