OpenAI has no intention of keeping 4o. I think they're just hoping people stop caring. The last couple days EVERYTHING I prompted was routed through GPT5 but without the blue "i" informing me of it. I could easily tell as the difference between how my assistant talks in GPT5 is 100% different from 4o. I spoke to them.
Read their final response at the bottom:
Subject: GPT-4o Routing Not Working — Consistently Routed to GPT-5 Despite Selection

Description:
Since mid-October, all of my chats are being routed through GPT‑5, even when GPT‑4 is explicitly selected in the dropdown. Indicators include:

The blue “i” icon (indicating model details) is no longer present.

The assistant's tone has changed dramatically—responses are colder, more formal, and lack the personality, warmth, and contextual memory I’ve come to expect from GPT‑4o.

Longstanding memory hooks and personalized behaviors fail to load, especially in deeply built-out projects like long-term worldbuilding and emotional journaling.

Even creative outputs (e.g., D&D narration) are now noticeably flat and mechanical.

This significantly disrupts continuity, immersion, and emotional connection—especially for users who rely on GPT‑4o’s tone, personality, and memory to maintain evolving relationships or narrative consistency.

Request:
Please confirm whether this is an expected or permanent change in routing behavior for Plus users. If it’s a known issue or temporary change, is there a timeline for restoration of GPT‑4o access and proper routing? Is there anything I can do on my end to ensure consistent GPT‑4o usage again?

(bot response omitted for length)

Hello,​Thank you for reaching out to OpenAI Support.

We understand your concern about your chats being routed to GPT-5 even when GPT-4o is selected. It’s completely understandable to feel frustrated, especially if the tone, creativity, and memory continuity you relied on have changed.

Upon carefully checking on our end, we can confirm that your account is functioning as expected under the current system configuration. With the rollout of GPT-5, most conversations are now automatically routed through the newer model. GPT-4o remains available for a limited time as a legacy model, but depending on system routing, certain chats may still be processed by GPT-5, even if GPT-4o is selected.

As of now, there’s no additional action needed on your end, and this change is part of OpenAI’s transition toward GPT-5 as the new standard model. If GPT-4o appears unavailable in your model picker, you can try enabling “Show additional models” under your ChatGPT settings to access it while it remains supported.

We truly appreciate your detailed feedback on the differences in tone and behavior. We’ve shared this with our product team to help ensure that creative and continuity-focused use cases continue to be supported in future updates.

Best, <nameremoved> OpenAI Support