Nope, or technically true only to some limited extent. Briefly, it's 130 km/h only if there is no ETCS on the line (even ETCS L1LS, but it's used only on one line which tops up at 120 km/h, the rest is L1 or L2, if it's L1 then usually it uses no infills, so then you get the usual L1 over-enforcing driving experience), but what's more important, is that in Poland trains cannot exceed 160 km/h, when the line (or the vehicle) is not fitted with ETCS. If there is ETCS in both, you're free to drive the line speed, be it 160 km/h or 200 km/h, with a single driver in the cab.
As an interesting fact, Poland, in fact, did some trickery calling their own old system called SHP (Samoczynne Hamowanie Pociagu, literally Automatic Train Braking) a "class B" system according to the EU regulations (proof:
https://www.era.europa.eu/system/files/2022-11/List of CCS Class B systems.pdf, and class B systems apparently are everything bar ETCS, even if they provide features very much alike ETCS L1, like German LZB). The problem is, SHP does nothing except triggering additional dead man's switch check every passed signal - it uses only one resonant frequency which is completely independent of the signal. It seems in the old days (80s?) there were some plans for making it a real train protection system, but apparently this was too much of a task to ensure right electromagnetic compatibility for that with diverse systems used in signal boxes throughout Poland and it seems that they gave up.
Such restictions aren't also only specific to Poland. On DB Netz network, one cannot drive over some speed, when there's no LZB nor PZB on the line. And this speed, is...
100 km/h. So, given that there is no real train protection system on Polish lines unfitted with ETCS, maybe this restriction does make some sense? (I'm not making a definite point on this, though, personally I have no opinion on this issue, and the Polish railway industry lately seems to be very divided on that)
As a finishing note, what I wrote above refers to the PKP PLK network, but there isn't a lot of other owners' railways in Poland, particularly with line speeds above 40 km/h, except some light railways which may go up to 70 km/h, but as far as light railways usually go, it's reached with no or minimal signalling (another curio: because of much more diverse usage of the light railway network in Poznan, Poland in latest years, traditional, manual, physical token "signalling" is currently used on less-utilised some parts of it, and apparently, is doing its job pretty great).
(in the proof link I've posted above, there's also a mention on Polish "radio-stop" system, which is a dirt simple system based on sending a predefined constant DTMF sequence over analog radio which forces emergency braking of all trains which have heard this sequence, not a very good thing to rely on, as if the radio in cab is tuned to another channel, that's enough to make it miserably fail, and radios in signal boxes usually are programmed to be confined to one channel, but anyway, this little "system" has saved careless signallers' and drivers' arses numerous times, sometimes saving human lives and rolling stock, as well)
