In the C++ implementation, polylines use version '2' for their compressed format:

https://github.com/google/s2geometry/blob/master/src/s2/s2polyline.cc#L73-L74

static const unsigned char kCurrentCompressedEncodingVersionNumber = 2;

But the Go implementation seems to share polyline and polygon encoding implementations here:

https://github.com/golang/geo/blob/master/s2/encode.go#L29C1-L31C37

// encodingCompressedVersion is the current version of the
// compressed format.
encodingCompressedVersion = int8(4)

So, the Go S2 implementation cannot in fact read the compressed S2 Polyline, because it triggers the version mismatch check: