this is simply false: bluesky moderating your account will have no effect on what happens with it on tangled. on the off-chance that your account is hosted by bluesky's PDS AND your account gets deleted for violating their terms, yes, you will lose complete access to that account. you can avoid this by either following their TOS or hosting your own PDS or joining the tangled PDS instead.

or keeping your own plc rotation key and a backup of your user repo, then you can migrate even after bluesky issues a takedown on your user.