I think he was just not paying attention to it. He seemed very focused in the fight. And the SSJ2 was also a quick burst, maybe the meter couldn't pick it up similar to scouters.
If you think Goku was suppressed for the 3000, then surely it wouldn't be just a quick burst? He would have powered up to the max of SSJ1 and then gone to SSJ2. He would have noticed it increasing on the way to SSJ2, unless the meter was maxed out or the meter was unable to read the energy due to Yakon absorbing it and spreading it out.
Maybe but I'd find it hard to believe. SSJ2 Gohan made the meter malfunction and spin around rapidly. You'd have to think it would be making noise if that was the case. Goku is even stronger than Gohan...
Wouldn't the meter be more likely to malfunction if its max possible reading was 3000, compared to if the max was above 3000?
Reasons I can see the meter not malfunctioning would be:
1. It's too slow to detect PLs and it's only the jump from SSJ1 to SSJ2 that causes the malfunction. Goku turned SSJ2 just before Yakon died (one panel prior, plus has the sound effect), so wasn't SSJ2 for long (supported by Vegeta saying "it looks like Kakarot can" exceed a Super Saiyan, which sounds like he only briefly saw it). Meanwhile Gohan was SSJ2 for long enough for onlookers to have a short conversation.
2. The meter is fast enough, but Goku in that brief moment never hit the same level of power as Gohan. This is supported by Goku being calm while Gohan was still angry about Spopovich and about having to mess up his school life (so he was just in "fuck it" mode, which is why he decided to show his full power rather than just the requested SSJ1). It's also supported by Vegeta "looks like he can exceed the level of a SS" comment" - he says "can", rather than "has", which could mean he didn't truly hit SSJ2, but only got to a point where his hair changed and he was starting to get a more erratic ki.
3. The meter at the tournie was a weaker meter. We know Bab had multiple meters, since he asked for the highest one to measure Goku. He was shocked by Base Vegeta being leagues above PuiPui, so he might've sent Yamu/Spopovich with a weaker meter that maxes out around Base, thinking that's above what would be available at the tournament. Kinda makes no sense though, since Yamu/Spop were looking for specific people (otherwise they'd just wait until the final), so how strong were they expecting the saiyans to be/what were their instructions on what to look for? Did they never see the Cell Games? Did they just know some people existed who were way above normal human fighters? If Krillin or even Roshi had showed his true power would they have kidnapped him?
4. Yakon absorbing the energy made the meter pick up a lower reading, which allowed it to not malfunction. If it's picking up the volume of energy reaching it and using that to figure out how much energy is at the source, then maybe Yakon stealing it is reducing the flow of the radiation of energy to the meter. Or if the volume of ki isn't what causes a power increase but rather the ki energy per particle (or whatever ki is made up of) that changes, then it might not matter that Yakon is absorbing some of it, since the meter only needs to detect one particle to know the power per particle. Or it could be a combination of both - having a higher ki power can be attained through having more ki particles per second or also by having more power per particle, in which case again Yakon absorbing some of the energy would mess up the reading.