All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.
Shaving the beard is prohibited because we were commanded by the Prophet, sallallaahu ‘alayhi wa sallam, to grow it. [Al-Bukhari and Muslim]
However, one may shorten what grows longer than a hand fist’s length, since this was done by Ibn ‘Umar and Abu Hurayrah .
As for your question whether shaving or shortening the beard deprives a Muslim from getting to the 'Hawdh (Basin) of the Prophet, sallallaahu ‘alayhi wa sallam, then we do not know any authentic narration about this.
All that can be said about shaving or shortening a beard is that it is an act of disobedience to Allaah The Exalted, but whoever sincerely repents to Allaah, Allaah will accept his repentance and forgive his sin. If a person dies upon Islamic belief and creed, he will go to the 'Hawdh (Basin) of the Prophet, sallallaahu ‘alayhi wa sallam, Allaah willing, on the Day of Resurrection and he will drink one sip after which he will never feel thirsty.
Allaah Says (what means): {O you who have believed, repent to Allaah with sincere repentance. Perhaps your Lord will remove from you your misdeeds and admit you into gardens beneath which rivers flow [on] the Day when Allaah will not disgrace the Prophet and those who believed with him. Their light will proceed before them and on their right; they will say, "Our Lord, perfect for us our light and forgive us. Indeed, You are over all things competent.}[Quran 66:8]
Allaah Knows best.