What makes you think it is an interpolation? If you think it is then, by whom?
OK, so you didn't look into it. That's fine. Here's something if you want to investigate > Why would 1 Cor 14:34-35 be an interpolation?
These are the basic points (from another website):
Payne starts with a list of five hallmarks of interpolations in which he draws parallels between 1 Cor 14:34-35 and the PA in John 7:53–8:11:
1. In both, the doubtful verses occur at different locations in the text.
2. Manuscripts of both display a high concentration of textual variations.
3. Both contain word usage atypical of the book’s author.
4. In both, the doubtful verses disrupt the narrative or topic of the passage.
5. In both, marginal symbols or notes indicate scribal awareness of a textual problem. In particular, Vaticanus has a distigme at the beginning of both passages.
2. Manuscripts of both display a high concentration of textual variations.
3. Both contain word usage atypical of the book’s author.
4. In both, the doubtful verses disrupt the narrative or topic of the passage.
5. In both, marginal symbols or notes indicate scribal awareness of a textual problem. In particular, Vaticanus has a distigme at the beginning of both passages.
I frankly don't think the issue is that big of a deal. I can't say it's an interpolation or not, but the evidence is certainly strong enough to be not dogmatic about the issue.