That is a danger, but for now it seems rather distant.
OpenAI has provided in the past a couple of open-weights models, but it does not seem to plan the release of any others.
But except for OpenAI and Anthropic, with this announcement Zyphra is the 12th company which has announced new improved open-weights models during the last couple of months.
A half of these 12 companies have launched not only small models with less than 128B parameters, but also big models with a number of parameters ranging from over 200B to over 1T.
So for now there is a healthy competition and the offerings in open-weights models are very diverse and numerous.
(The 12 directories on huggingface.co: deepseek-ai, google, ibm-granite, LiquidAI, MiniMaxAI, mistralai, moonshotai, nvidia, Qwen, XiaomiMiMo, zai-org, Zyphra.)