I can understand your concern here because almost most of users are using windows over other OSs for the reasons we all know. Thank you for sharing the info.
Based on what you mentioned, i have two questions :
1. I have an old cell phone i bought it on 2019. I installed electrum at that time and didn't update it since then (can't tell if the updates was done automatically) and then i left that cell phone since 2020. Last January i re-opened Electrum in that mobile , i found that i am not able to create a new seed (i have already three previous wallets). Anyone has an explanation?
2. An old laptop i use since 2019 as a cold storage. The device has windows 7 installed but never updated and an old version of electrum (can't remember the version). Should i upgrade Electrum if i want to keep using the same laptop without upgrading the OS version?
If you bought your phone year 2019 you will need to upgrade the Electrum app your Electrum version might be lower than 3.3.4 it is no longer supported due to vulnerability to phishing attacks. Unless you installed a higher version than 3.3.4 it should be work fine but if it can't able to create a new seed you might need to reinstall the Electrum app make sure you have a backup seed phrase to recover your old wallet.
You can download the same version here
https://download.electrum.org/ or download the latest one if you don't want to connect it to the internet you can use an SD card to transfer the downloaded Electrum apk from PC to your phone.
About your 2nd question if it's cold storage you don't need to upgrade it will work just fine.