I am currently I USA on L-1 status. I got a new job and my new employer is going file a cap exempt H1B ( based on a previously approved H-1B). USCUIS stopped premium processing on all I-129s today due to COVID-19. Can I still join my new employer based on USCIS receipt?
No, because this is not an H-1B transfer of employer. You must wait until your H-1B petition is approved.
https://www.avvo.com/legal-guides/ugc/green-cards-through-employment
No, you cannot do so. If you have a company immigration attorney, these questions should be directed to your immigration attorney. Your questions should be directed to your company's immigration attorney, since the attorney is the person most familiar your case. But remember this attorney is the company attorney, not yours. Immigration is a very complex area of law. It is a lot more than merely filling out forms. You need to retain an immigration attorney to handle all immigration proceedings. This prevents errors that can sometimes prove costly and may even be irreversible. You should always seek to obtain the best attorney that you can afford and not let geographic restrictions stand in the way. Some immigration attorneys will charge a consultation fee, however those that do so, will give full credit if you retain their law firm. Do not let geographic restrictions prevent you from obtaining the best possible attorney. Pick the best lawyer you can find and remember one rule: a good lawyer is generally never cheap, and a cheap lawyer is generally never good so don't choose based on price. Good luck.
No, you can not start a CoS from L to H with nothing more than a fee receipt.