Not quite...
I believe playing in the Olympics could cap tie you if you are 21 or older and only eligible to play for one nation at the time you play. I know from looking it up previously that Zawada is cap tied to Poland due to one too many appearances for a Poland u23 team when he was 21.
And if you are eligible to play for multiple countries, then in some circumstances, playing one or two games in a competitive senior international tournament may not cap tie you, this from Wikipedia:
"If a player was eligible to play for multiple nations prior to making a competitive appearance, they are cap-tied to a nation after playing more than three matches for one national team, including at least one competitive appearance (if the player is under 21 at the time, no matter the level of competition, as long as they have not played in the finals of a major tournament), or after making a competitive appearance (if the player is over 21 at the time and the appearance is for the senior team). Allowing young players to play a couple games before becoming cap-tied was a change to the rules announced during the 2020 FIFA congress, with the hope to prevent "one-cap wonders"; it was seen as an opportunity for some dual-national players, like Spanish-Moroccan Munir El Haddadi, who were called up as promising players for European nations, but not afforded more than one or two caps, to elevate the level of their African heritage nations."
Edit: actually, upon reading that again, maybe the Oceania nations cup is considered the finals of a major tournament, in which case maybe any appearance there does the job. In any case, if the Wikipedia page on this is anything to go by, it's all rather complex and confusing.
Edit 2: the Forbes article the Wikipedia article cites seems to make it clear that an appearance the ONC would cap tie a player
I believe playing in the Olympics could cap tie you if you are 21 or older and only eligible to play for one nation at the time you play. I know from looking it up previously that Zawada is cap tied to Poland due to one too many appearances for a Poland u23 team when he was 21.
And if you are eligible to play for multiple countries, then in some circumstances, playing one or two games in a competitive senior international tournament may not cap tie you, this from Wikipedia:
"If a player was eligible to play for multiple nations prior to making a competitive appearance, they are cap-tied to a nation after playing more than three matches for one national team, including at least one competitive appearance (if the player is under 21 at the time, no matter the level of competition, as long as they have not played in the finals of a major tournament), or after making a competitive appearance (if the player is over 21 at the time and the appearance is for the senior team). Allowing young players to play a couple games before becoming cap-tied was a change to the rules announced during the 2020 FIFA congress, with the hope to prevent "one-cap wonders"; it was seen as an opportunity for some dual-national players, like Spanish-Moroccan Munir El Haddadi, who were called up as promising players for European nations, but not afforded more than one or two caps, to elevate the level of their African heritage nations."
Edit: actually, upon reading that again, maybe the Oceania nations cup is considered the finals of a major tournament, in which case maybe any appearance there does the job. In any case, if the Wikipedia page on this is anything to go by, it's all rather complex and confusing.
Edit 2: the Forbes article the Wikipedia article cites seems to make it clear that an appearance the ONC would cap tie a player